Abstract:Glucosyltransferase plays an important role in plant stress resistance and development regulation. In order to explore the members of the glucosyltransferase BnIRX14 gene family and analyze its biological function in Brassica napus, the study based on BnIRX14, which was cloned from B. napus and adopted the methods of sequence comparison and genetic transformation, we identified BnIRX14 gene family members and conducted functional verification to explore the regulation mechanism of BnIRX14 gene family in B. napus development, and to provide theoretical basis for cross breeding and resistance breeding in B. napus. The results showed that: (1) 11 BnIRX14 family members belonging to 3 different subfamilies of glucosyltransferase were successfully identified in B. napus by genomic database comparison analysis. All of them had the domain characteristics of glucosyltransferase GT43 family members, among which 8 genes were located on 6 different chromosomes. 3 subfamilies showed great specificity in gene structure and conserved elements. (2) Twenty transgenic B. napus lines with BnIRX14 RNA interference were obtained by Agrobacterium-mediated transformation, and 5 positive transformation lines were identified by PCR. (3) Phenotypic identification showed that there was a hole-like cavity from the top to the center of the stigma of the two positive transformation lines, the ovary was significantly enlarged than that of the wild type, and the stigma was not fertile after pollination, indicating female sterility. The other three positive plants had normal flower structure, but the stem and branch of the plants had liquid exudation, which adhered to the surface of the stem and branch in the shape of dew. (4) Real-time quantitative PCR(RT-qPCR) analysis showed that the BnIRX14 gene expression in the flowers, kernels and leaves of B. napus transgenic positive plants was significantly lower than that of the wild type, and the BnIRX14 gene expression in the kernels of the 9# positive sterile plant was lower than that of other transgenic interference lines. The results showed that BnIRX14 gene expression was significantly inhibited in the interference-transformed positive plants. It is speculated that BnIRX14 gene may be involved in pistil development and metabolism of secondary substances in rape.

Abstract:Dihydroflavonol-4-reductase (DFR) is a key enzyme in phycocyanin synthesis that catalyzes the production of colorless anthocyanins from dihydroflavonols. In this experiment, petals from different organs and different developmental periods of red and white Rhododendron hybridum Hort. were used as experimental materials, and the RhDFR gene of R. hybridum Hort. was cloned with reverse transcription (RT-PCR) and RACE techniques, and the plant enzyme-linked immunoassay kit (ELISA) was used to determine petal RhDFR enzyme activity of petals at different developmental stages, and the qRT-PCR technology was used to quantify the petal RhDFR gene in different organs and different developmental stages, and the preparation and purification of RhDFR protein by pET-28a-RhDFR prokaryotic expression vector was constructed, which laid a foundation for further exploration of the function of Rhododendron DFR gene and the molecular mechanism of flower color. The results showed that: (1) successful acquisition of R. hybridum Hort. RhDFR gene is 1 253 bp long, an open reading frame of 1 035 bp, encoding 344 amino acids, and contains a NADPH-binding region and a substrate-binding region with high conservation. Phylogenetic analysis showed that R. hybridum Hort. RhDFR protein is most closely related to the DFR protein of lingonberry (Vaccinium corymbosum). (2) The analysis of ELISA kit showed that the DFR enzyme activity of petals showed in different stages of development of R. hybridum Hort. first increased and then decreased, and the DFR enzyme activity was the highest in the middle opening stage of red flower and full opening stage of white flower. (3) The qRT-PCR analysis showed that the expression of RhDFR gene in different organs was the highest in petals, and the lowest in stamens; In petals at different developmental stages of development, red flowers had higher RhDFR gene expression than white flowers. (4) The prokaryotic expression vector pET-28a-RhDFR was successfully constructed and induced to express a protein with a size of about 38 kD, which was similar to the theoretical value. It is believed that the function of DFR enzyme activity in Rhododendron is diversified, and the DFR gene is related to the color of R. hybridum Hort. petals.

Abstract:In order to explore the function and expression characteristics of ZmPRR1-2 gene and analyze the mechanism of the flowering regulation by photoperiod pathway in maize, we cloned cDNA sequence of the ZmPRR1-2 gene in the maize backbone inbred line ‘Huangzao 4’ and analyzed by bioinformatics. Tissue-specific expression analysis and 48 h circadian rhythm expression analysis of the gene were performed using qRT-PCR. The results showed that: (1) the full-length coding region of ZmPRR1-2 gene was 1 554 bp, encoding 517 amino acids. The encoded protein belonged to the PRR gene family, containing one REC domain and one CCT domain. Multiple sequence alignment and phylogenetic analysis showed that ZmPRR1-2 gene was highly conserved in Poaceae plants. ZmPRR1-2 is a hydrophilic protein without transmembrane domain and signal peptide. (2) Tissue-specific expression analysis showed that the expression of ZmPRR1-2 gene in leaves was significantly higher than that of the other seven tissues, which indicated that ZmPRR1-2 gene mainly functions in the leaves, while the expression level in ear and silk was relatively low, and significantly lower than that in tassel. (3) Circadian rhythm expression analysis showed that under short-day conditions, the expression level of ZmPRR1-2 gene began to increase gradually after 3 h of light, and reached the peak at 3 h after the end of light. Under long-day conditions, the expression level of ZmPRR1-2 gene began to increase gradually after 6 h of light, and reached the peak at the end of light. It is suggested that ZmPRR1-2 gene has different regulatory functions on tassel development and ear development during maize flowering transformation. ZmPRR1-2 gene may play an important role in the regulation of maize circadian clock.

Abstract:In this study, the differentially expressed sequence ES816317 was cloned based on the differential expression sequence results of the low phosphorus stress gene expression profile chip in the roots of Gossypium hirsutum L. and the genome database. We used bioinformatics methods to analyze its nucleotide and protein. Its tissue expression pattern and relative expression under low phosphorus stress were detected by using qRT-PCR technology, so as to lay the foundation for analyzing the biological function of GhCSN6A in G. hirsutum and provide genetic resources for cotton phosphorus efficient genetic engineering breeding. The results showed that: (1) GhCSN6A gene of G. hirsutum L. was successfully cloned, and the full length of the open reading frame of the gene was 948 bp, encoding 315 amino acids. GhCSN6A protein, called COP9 signalosome complex subunit 6a, belonged to the MOV34 protein superfamily, had an MPN_CSN6 domain, and was localized in the nucleus. (2) Sequence alignment and evolution analysis showed that the similarity of GhCSN6A to HsCSN6A and AtCSN6A was 95.87% and 84.54%, respectively, so the gene was named GhCSN6A. (3) qRT-PCR analysis showed that GhCSN6A was expressed in all tested tissue including root, stem, leaf and flower, and the expression level was the highest in leaf, but there was no significant difference between leaf and root. The relative expression of GhCSN6A gene was the lowest in the root treated with low phosphorus for 24 h. However, the highest in the root treated with low phosphorus for 72 h, which was twice that of the suitable phosphorus (control) treatment. The study has speculated that GhCSN6A gene played an important role in the response to low phosphorus stress in G. hirsutum.

Abstract:The study was based on full-length transcriptome data from Nitraria tangutorum, and the seedlings of N. tangutorum were used as experimental materials, NtBES1 family members from the transcriptome were identified and bioinformatics analysis were carried out; in addition, quantitative Real-time PCR was applied to analysis the expression patterns of NtBES1s in leaves treated with different concentrations of PEG and NaCl, which lay the foundation for the in-depth study of function of NtBES1 family members and molecular mechanism of stress resistance in N. tangutorum. The results showed that: (1) a total of 7 NtBES1s with complete BES1_N conserved domains were identified, and they were named as NtBES1-1-NtBES1-7; (2) the amino acids number of NtBES1 protein ranged from 86 to 422 aa, the molecular weight ranged from 9.75 kD to 47.53 kD, the isoelectric point ranged from 5.29 to 10.22, the instability index ranged from 34.88 to 75.02, and the average hydrophilic coefficient was negative; (3) the prediction results of subcellular localization showed that NtBES1-6 was localized in the cytoplasm, and the remaining 6 members were localized in the nucleus; (4) the seven NtBES1s were divided into three groups by phylogenetic tree, NtBES1-2, NtBES1-3 and NtBES1-7 were a group, NtBES1-1, NtBES1-5 and NtBES1-6 were a group, and NtBES1-4 was a single group, and the structure, physicochemical properties and functional annotations of the members in same groups were similar; (5) the three genes with high expression levels screened in the pre-experiment showed different expression patterns under stress: NtBES1-2 and NtBES1-6 were upregulated only at 30% PEG treatment for 2 h; under NaCl treatment, NtBES1-2 and NtBES1-4 showed the highest expression at 200 mmol/L treatment for 2 h, after 450 mmol/L treatment for 12 h, the expression level of these three genes gradually began to up-regulate, and reached to their highest levels at 24 h. The research shows that there are differences in the structural characteristics of NtBES1s, and different members play different roles in drought and salt tolerance process.

Abstract:The Actinidia chinensis Aux/IAA gene family was identified and analyzed by bioinformatics in this study. Their physicochemical properties, structural characteristics, synteny relationships were analyzed by bioinformatics, tissue-specific expression patterns and exogenous hormones stress responses were also analyzed by qRT-PCR, which lay the foundation for elucidation the biological function of Aux/IAA family during kiwifruit development. The results showed that: (1) 50 Aux/IAA candidate genes were identified in the A. chinensis genome and they were located on twenty-one chromosomes, and with Chr 23 residing the largest number of 11 Aux/IAA genes (AcIAAs). The amino acid size, molecular weight, and isoelectric point ranged from 125-391 aa, 14.06-42.48 kD, 4.33-9.51, and 0-5, respectively. Phylogenetic analysis divided these genes into nine subfamilies. (2) Most AcIAAs contained 4 different conservative domains, most of the members contain Ⅱ, Ⅲ and Ⅳ domains, and some genes lack Ⅰ domain. There were 1-5 introns in the AcIAA genes based on the gene structure analysis. Also, 23 pairs of AcIAA genes were found underwent segment duplications, which including 20 pairs of fragment repeats and 3 pairs of tandem repeats. Moreover, thirty-six pairs orthologous gene were observed between A. chinensis and Arabidopsis. (3) Stress responses, hormone response and tissure specific related cis-elements were abundant in the promoter region of the AcIAA genes. Subcellular localization analysis indicated that most AcIAA located in the cell nuclear. (4) qPCR analysis showed AcIAAs showed tissue-specific expression，and differential response time and intensity under exogenous hormones treatment. Most of the genes were down-regulated at the early stage of treatment, while the gene AcIAA1a and AcIAA18a were up-regulated. The difference of response mode showed that the Aux/IAA family genes may had different functions during the regulation of A. chinensis development. The research suggests that Aux/IAA family genes have functional diversity in A. chinensis, and some of the genes with gene duplication show similarity in tissue expression patterns. It is speculated that there may be redundancy in function of Aux/IAA genes, or gene sequence deletion or gene duplication due to environmental stress in the evolutionary process of A. chinensis.

Abstract:Under the background of global climate change, screening urban greening plants with strong drought tolerance is an important way to deal with the shortage of groundwater resources and urban greening construction in the future. In this paper, Camellia japonica and Rhododendron hybridum were used as materials, and the drought resistance of petals and leaf tissues of them during water stress were compared. The embolism vulnerability curves of petals and leaves were constructed by optical technology, and the morphological and structural characteristics of petals and leaves in C. japonica and R. hybridum were observed. The results showed that: (1) there was no significant difference in the water potential of the soil where C. japonica and R. hybridum were grown under natural drought, and both were significantly reduced from day 9 compared with the control. The water potential of R. hybridum leaves and petals decreased significantly on day 9 after the natural drought, while the water potential of the leaves and petals of the C. japonica leaves decreased significantly when the natural drought lasted until day 12. (2) The P50 (the corresponding water potential when 50% embolism occurred) values of petals and leaves of R. hybridum were -3.24 MPa and -4.40 MPa, respectively, which were higher than those of C. japonica (-3.99 MPa for petals，and -5.92 MPa for leaves). (3) There was no significant difference in the thickness of petals and the thickness of upper and lower epitheliums between C. japonica and R. hybridum, while the veins density and stomatal density of C. japonica petals were significantly greater than those of R. hybridum; C. japonica leaves thickness, upper and lower epithelium thickness, sponge tissue thickness and leaf veins density were significantly greater than those of the R. hybridum. The embolism vulnerability of C. japonica and R. hybridum is related to its tissue morphological structure, the thicker the leaf thickness, the upper and lower epidermis thickness and the sponge tissue thickness, the less embolism vulnerability there is. In the case of increasing drought in the future, C. japonica can be preferentially selected as a flower plant for urban greening.

Abstract:In order to explore the influence of different soil moisture treatments in different orchards on Fuji apple fruit quality, we focused on the differences in appearance quality, screened the most suitable water control method used in production. With the Fuji apple variety ‘Yanfu 3’ as material, we divided soil water treatment into two groups: group 1 with LT1 (55%-65%), LT2 (65%-75%), LT3 (75%-85%) and group 2 LT4 (earlier stage 55%-65%, later 45%-55%), LT5 (earlier stage 65%-75%, later 55%-65%), LT6 (earlier stage 75%-85%, later 65%-75%), with physiological fruit drop as the node to divide the early and late treatment, and ordinary orchard management as the control (LCK). The soil water content and soluble solid content of fruit were determined, the crack index, coloring index and smoothness index of fruit were calculated, and the ultrastructure of fruit peel was observed by scanning electron microscopy. The results showed that: (1) compared with the control, soluble solid content of fruit treated by LT1, LT4 and LT5 increased by 13.4%, 15.2% and 13.1%, respectively. (2) The crack index of LT2, LT3, LT5 and LT6 fruits decreased by 49.8%, 19.8%, 49.8% and 30.1%, respectively. LT1, LT2 and LT5 increased the fruit coloring index by 3.4%, 14.0% and 17.4%, respectively. LT1-LT6 treatments increased fruit smoothness index by 50.4%, 150.4%, 125.6%, 45.2%, 175.9%, 100.8%, respectively. (3) The changes of peel microstructure showed that the instability before and after water control could lead to severe cuticle cracking, which was avoided by LT5 treatment. The cuticle thickness of healthy fruit was larger than that of split fruit. (4) The water potential of healthy fruit (-1.22 MPa) was significantly higher than that of cracked fruit (-1.44 MPa), and the water potential of fruit was negatively correlated with the occurrence of crack. In conclusion, appropriate soil water stress (65%-75%) can significantly reduce the incidence of fruit surface cracks and improve the fruit surface finish without affecting the edible quality of the fruit; In the late stage of fruit development, appropriate light water treatment will promote the accumulation of sugar and reduce the occurrence of cracks in the fruit; The occurrence of fruit cracks is related to the thickness of peel cuticle and fruit water potential. The greater the thickness and the higher the water potential, the less cracks occur. The apple fruits treated with LT2 and LT5 had both good edible quality and appearance quality.

Abstract:‘Nanfeng tangerine’ was used as the experimental material in this study. The fruits sprayed with 0.14 g/L chelating calcium on the fruit surface before high temperature coming (June) as calcium treatment, and the fruits sprayed with water were the control. The calcium signal transduction and antioxidant enzyme gene expression levels, antioxidant enzyme activities and reactive oxygen species (ROS) contents were determined. In addition, the gene expression characteristics of antioxidant enzymes regulated by the genes of calcium signal transduction pathway in ‘Nanfeng tangerine’ peels during the sunburn occurrence period with calcium treatment were analyzed to reveal the molecular and physiological mechanism of calcium alleviating the tangerine sunburn disease, and to provide a theoretical basis for preventing and reducing sunburn physiological disease of tangerine in the fruit production by spraying chelating calcium. The results showed that: (1) the incidence of sunburn in ‘Nanfeng tangerine’ fruits treated with calcium was significantly lower than that of the control, which decreased by 13.76%. (2) The results of real-time fluorescence quantitative PCR revealed that the expressions of calcium signaling pathway-related genes CsNADK, CsMPK8, CsCPK, CsRBOH, CsCAMK1 and CsGAD, and antioxidant genes CsSOD, CsCAT, CsPOD, CsAPX, CsGSR and CsGPX in the ‘Nanfeng tangerine’ peels were significantly up-regulated by calcium treatment. (3) The activities of antioxidant enzymes SOD, CAT, POD, APX, GR and GPX were significantly increased, and the contents of ₂^-·, H₂O₂ and MDA were significantly reduced in ‘Nanfeng tangerine’ peels by calcium treatment. (4) Fluorescence staining results revealed that the peel cells produced excessive green fluorescence of ROS, and the fluorescence accumulated diffusely with the duration of stress, while the ROS fluorescence intensity was significantly weaker in all calcium treatments than that in the control during the period of high temperature and intense direct light stress from July to October. These results indicated that the up-regulated expressions of calcium signaling pathway-related genes regulated the antioxidant gene expression and the enzyme activities, scavenging excess ROS and maintaining the balance of ROS metabolism in the tangerine peels, thus improving the anti-sunburn ability of the tangerine peels. A simple and effective technical measure to prevent sunburn in tangerine production is to spray chelating calcium on the fruit surface before the high temperatures coming.

Abstract:Lycium barbarum is a famous salt-tolerant medicinal plant, this study conducted through indoor hydroponics experiments. High-throughput sequencing technology and qRT-PCR technology were used to determine the differential expression of photosynthetic related genes in leaves of L. barbarum under different concentrations of NaCl (0, 100, 200, 300 mmol/L), and the changes of chlorophyll content, net photosynthetic rate and Rubisco activity were analyzed.The purpose of this study was to reveal the differential expression of photosynthetic mechanisms and photosynthesis related genes of L. barbarum under salt stress, which laid the foundation for further analysis of the photosynthetic mechanism of L. barbarum in response to salt stress.The results showed as follows: (1) 14, 26 and 55 photosynthesis related genes were differentially expressed when treated with 100, 200 and 300 mmol/L NaCl for 7 days, respectively, the down-regulated genes were more than up-regulated genes with the increase of NaCl stress. (2) The results of qRT-PCR showed that the relative expressions of ATPε, CLH2 and Lhcb3 of the three photosynthetic related genes of L. barbarum showed a significantly decreased trend with the increase of NaCl stress. The results of qRT-PCR verification were basically consistent with the results of RNA-seq sequencing. (3) With the increase of NaCl stress, the contents of chlorophyll a and chlorophyll b, the net photosynthetic rate and the activity of Rubisco in the leaves of L. barbarum decreased significantly, but the carotenoid content did not change significantly. It was suggested that L. barbarum could regulate leaf photosynthetic activity in response to NaCl stress by inducing the differential expression of photosynthesis related genes.

Abstract:In this experiment, we used the seedlings of the main constructive species of Reaumuria soongorica in the desert area as the experimental material, and set four different water treatments including suitable water (CK), light drought stress (MD), moderate drought stress (SD) and serious drought stress (VSD), i.e., 80%, 60%, 40% and 20% of the water holding capacity in the field. The contents of non-structural carbohydrates (NSC) and their components in leaves, stems, coarse roots and fine roots of R. soongorica seedlings at 15 d, 30 d, 45 d and 60 d of drought stress were measured by pot water control experiment. The dynamic changes and differences of components of NSC in R. soongorica seedlings under different stress intensities and drought durations were analyzed, aim to reveal the response mechanism of R. soongorica NSCs to drought stress. The results showed that: (1) the intensity and duration of drought stress had a significant effect on the NSC and their components of different organs in R. soongorica seedlings, and the duration of stress had a particularly significant effect on the dynamic changes of NSC. (2) In the early stage of drought stress, the NSC content in leaves of R. soongorica showed a downward trend, while the NSC content in stems showed an upward trend, and the NSC content in coarse roots and fine roots remained basically stable under various stress treatments. (3) In the late stage of drought stress, the soluble sugar, starch and NSC content in leaves and stems of R. soongorica gradually increased, while the starch and NSC content in coarse roots and fine roots showed a downward trend (except moderate drought stress), and during this period, the contents of soluble sugar and NSC in various organs under serious drought stress treatment is significantly higher than those of CK. The study found that severe drought stress could significantly induce the increase of NSC content in different organs of R. soongorica seedlings, and the balance of cell osmotic potential was regulated by decomposing starch in roots and increasing soluble sugar content in leaves to maintain cell vitality, thus maintaining the survival of R. soongorica in the late stage of drought stress.

Abstract:In order to investigate the physiological mechanism of sweet cherry rootstock under NaCl treatment, we studied the osmotic regulation substances, antioxidant enzyme activities, photosynthetic characteristics and chlorophyll fluorescence parameters of sweet cherry rootstocks ‘Gisela 6’ and ‘Colt’ seedlings under different concentrations (0, 50, 100, 150 mmol·L^-1) of NaCl solution with potted 1-year-old seedlings. The results showed that: (1) NaCl treatment promoted the accumulation of osmotic regulatory substances such as soluble sugar, soluble protein and proline in sweet cherry rootstock leaves. (2) With the increase of NaCl concentration, SOD activity in sweet cherry rootstock leaves showed an increasing trend, while POD activity increased first and then decreased. (3) With the increase of NaCl concentration, the net photosynthetic rate (P_n) and stomatal conductance (G_s) decreased gradually, while the intercellular CO₂ concentration (C_i) increased gradually in sweet cherry rootstocks. Non-stomatal limitation was the main factor for the decrease of P_n. (4) NaCl treatment inhibited the maximum photochemical efficiency (F_v/F_m), photochemical quenching coefficient (qP) and electron transfer efficiency (ETR), and increased non-photochemical quenching coefficient (NPQ) in sweet cherry rootstock leaves. In conclusion, salt stress destroyed the photosynthetic mechanism of sweet cherry rootstocks, inhibited the electron transfer rate and photochemical quantum efficiency, and reduced the utilization rate of light energy, resulting in the decrease of photosynthetic rate. Under the condition of salt stress, sweet cherry rootstocks can improve the adaptability to salt stress mainly increasing the content of osmotic regulatory substances and increasing the activity of antioxidant enzymes, relieving osmotic stress and reducing oxidative damage. ‘Gisela 6’ showed stronger adaptability and salt tolerance under salt stress. Sweet cherry rootstocks showed obvious symptoms of victimization when treated with more than 100 mmol·L^-1 NaCl.

Abstract:This study took Spirulina platensis as the experimental object to explore the effects of nitrogen concentrations (5, 15, 30 and 45 mmol·L^-1) and phosphorus concentrations (0.5, 1.5, 3.0 and 4.5 mmol·L^-1) on the growth, metabolites and chlorophyll fluorescence parameters of immobilized S. platensis, so as to provide a theoretical basis for large-scale and efficient cultivation of Spirulina. Results showed that: (1) with the increase of nitrogen and phosphorus concentrations in the culture medium, the biomass density and productivity of S. platensis increased first and then decreased, and reached their highest values at the nitrogen concentration of 30 mmol·L^-1 and phosphorus concentration of 3.0 mmol·L^-1. Low nitrogen and phosphorus concentrations affected the cellular structure of S. platensis, manifested as shorter single-cell filaments and fewer spirals, leading to the decrease of biofilm cell density. (2) Consistent with the S. platensis biomass, the content of photosynthetic pigments showed a trend of first increasing and then decreasing with the increase of nitrogen and phosphorus concentrations in the medium, and both reached the highest values at nitrogen concentration of 30 mmol·L^-1 or phosphorus concentration of 3.0 mmol·L^-1. (3) When the phosphorus concentration in the medium was fixed, the maximum light energy conversion efficiency (F_v/F_m) and electron transfer rate (ETR) of the PSⅡ reaction center of S. platensis increased with the increase of nitrogen concentration, and the lack of nitrogen affected the photosynthetic pigments synthesis, thereby weakening the photosynthesis of S. platensis. When the nitrogen concentration in the medium was fixed, the F_v/F_m and ETR of S. platensis showed a trend of first increasing and then decreasing with the increase of phosphorus concentration. (4) Although low nitrogen and phosphorus concentrations were not conducive to the increase of soluble proteins, they could stimulate the accumulation of soluble polysaccharides, and the more severe the limitation of phosphorus source was applied, the lower the protein content of S. platensis was produced, and the higher the polysaccharide content was accumulated. According to this study, the synthesis of high-value products such as Spirulina proteins and polysaccharides can be induced by adjusting the nitrogen and phosphorus concentrations in nutrients. Therefore, the synthesis and accumulation of corresponding target products can be promoted by adjusting the concentrations of nitrogen and phosphorus in production. The tolerance of S. platensis biofilm to nitrogen concentration was stronger than that of phosphorus concentration. The chlorophyll fluorescence parameters of S. platensis were higher under high nitrogen (45 mmol·L^-1) culture, and the biomass yield was also higher.

Abstract:To understand the relationship between the development of biological soil crusts and soil nutrient characteristics, this study selected moss crust (M-crust) and lichen crust (L-crust) at different stages of development, and analyzed the nutrients in the crust layer and the 3cm soil below the crust. The results show that: (1) the moss crust organisms were more bioenriched for TN, TP, Cu and Zn with enrichment coefficients up to 807.4%, 175%, 122.4% and 244.5%, respectively, while the lichen crust organisms were more bioenriched for TN, TP and Ca with enrichment coefficients up to 950.8%, 126.2% and 208.6%, respectively. And TP, Na, K, Cu, Fe, Mg, Mg and Zn except for Ca were significantly higher in moss crust organisms than in lichen crust organisms. (2) There was no significant linear correlation between the coverage of soil biological crusts and their soil nutrient contents in microhabitats, but the average TN, TP, Cu, Fe, K, Na and Ca contents in soils with different coverage of moss crusts were higher than those in lichen crusts. This study showed that different types of biological soil crusts have different nutrient uptake and enrichment efficiencies, and moss crusts in the late stage of development have stronger accumulation effects on nutrients than lichen crusts in the middle stage of development, which improve the nutrient storage capacity of soil and have potentially important impacts on the restoration and reconstruction of typical grassland ecosystems in Loess Plateau.

Abstract:The statistics of 15 new species and 77 newly recorded species of Orchidaceae in Tibet Autonomous Region in 2017-2022 showed that most of them (85.9%) were found in Medog County. Here, we investigated the wild orchid resources in Medog County in 2021. After critical survey of literatures and specimens, we have found that one newly recorded genus, viz. Cheirostylis Blume, and 10 new records of orchid species, viz. Bulbophyllum sinhoense Aver., Gastrodia putaoensis X. H. Jin, C. chinensis Rolfe, B. sasakii (Hayata) J. J. Verm., Schuit. & de Vogel, Dendrobium praecinctum Rchb.f., Cyrtosia falconeri (Hook. f.) Aver., Oberonia rufilabris Lindl., Rhomboda tokioi (Fukuy.) Ormerod, Tainia dunnii Rolfe and Zeuxine agyokuana Fukuy. in Medog County. In addition, B. sinhoense and G. putaoensis were two newly recorded species in China. The description of morphological characteristics, the anatomic photos of newly recorded species, and also the differences with similar species for identification are provided based on the fresh plants and the latest literature. All the voucher specimens are preserved in the Herbarium of East China Normal University (HSNU).

Abstract:Pre-mRNA from the same gene can produce different transcript isoforms after alternative splicing (AS), which changes the location, stability and post-translational modification function of the encoded protein in cells, enhancing the ability to growth & development and respond to environmental stress. Serine-arginine-rich proteins (SR proteins) is a kind of important splicing factor (SF) family that determines the efficiency and accuracy of AS. Based on a brief introduction of the concept and classification of SR proteins family, the authors systematically reviewed the structural characteristics, classification, subcellular localization and transcriptional regulation of SR-like (SR45/45a) subfamily in plant-specific SR proteins for the first time, summarized the AS regulatory mechanism of genes under biotic/abiotic stresses, and prospected several possible directions for the research of SR-like in the future.