干旱胁迫下外源硫化氢对烤烟幼苗光合荧光参数及抗氧化系统的影响
    点此下载全文
引用本文:李 冬,申洪涛,王艳芳,王丽君,赵世民,刘 领.干旱胁迫下外源硫化氢对烤烟幼苗光合荧光参数及抗氧化系统的影响[J].西北植物学报,2019,39(9):1609~1617
摘要点击次数: 0
全文下载次数: 0
作者单位
李 冬1,申洪涛2,王艳芳1,王丽君1,赵世民3,刘 领1* (1 河南科技大学 农学院河南洛阳 4710232 河南中烟工业有限责任公司技术中心郑州 4500163 河南省烟草公司洛阳市公司技术中心河南洛阳 471023) 
基金项目:国家自然科学基金(31700367);
中文摘要:为探究干旱胁迫下外源硫化氢(H2S)对烟草幼苗生长的缓解效应与机制,以烤烟‘豫烟6号’品种为试验材料,采用营养液水培的方法,研究15%聚乙二醇(PEG 6000)模拟干旱胁迫下,叶面喷施不同浓度(0、0.1、0.2和0.4 mmol·L-1)硫氢化钠(NaHS)对烤烟幼苗生长、活性氧代谢、抗氧化酶活性、叶绿素含量和光合荧光特性的影响。结果显示:(1)干旱胁迫下烤烟幼苗生长受到显著抑制。(2)外源H2S处理显著提高了干旱胁迫下烤烟幼苗的地上部与地下部生物量,增加了总根长、总根表面积、根平均直径、根尖数,提高了叶绿素相对含量(SPAD)、叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、光系统Ⅱ最大光化学效率(Fv/Fm)、光系统Ⅱ实际光化学效率(ΦPSⅡ)和光化学猝灭系数(qP),降低了胞间二氧化碳浓度(Ci)和非光化学猝灭系数(NPQ),增强了超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,降低了丙二醛(MDA)含量和超氧阴离子(O2-·)产生速率,其中以0.20 mmol·L-1 NaHS处理效果最佳。(3)与单独干旱胁迫处理相比,叶面喷施0.20 mmol·L-1 NaHS使烟苗地上部和地下部生物量分别提高了41.82%和44.83%,SPAD、PnFv/FmΦPSⅡ和qP分别提高62.88%、246.96%、8.43%、23.71%和10.84%,Ci和NPQ分别降低25.79%和22.68%,SOD、POD和CAT活性分别增加50.67%、140.59%和71.68%,MDA含量和O2-·产生速率分别降低40.08%和47.58%。研究表明,外源H2S处理通过提高烟草幼苗对光能的捕获与转换,增强光合作用,促进烟苗生长,并通过提高幼苗的抗氧化水平,减少干旱胁迫对烟草幼苗造成的氧化损伤,从而增强烤烟幼苗对干旱胁迫的适应能力。
中文关键词:烤烟幼苗  干旱胁迫  外源硫化氢  抗氧化能力  光合特性  叶绿素荧光
 
Effect of Exogenous Hydrogen Sulfide on Photosynthetic Fluorescence Parameters and Antioxidant System of Flue cured Tobacco Seedlings under Drought Stress
Abstract:Hydrogen sulfide (H2S) is a novel endogenous gaseous signal molecule that regulates plant stress resistance. To investigate the alleviation effect and mechanism of exogenous hydrogen sulfide (H2S) on tobacco seedlings growth under drought stress. This study adopted the method of nutrient solution hydroponics and used 15% polyethylene glycol (PEG 6000) to simulate drought stress. Flue cured tobacco (Nicotiana tabacum cv. ‘Yuyan No.6’) was tested for their response following foliar spraying with sodium hydrosulfide (NaHS) at concentrations of 0, 0.1, 0.2 and 0.4 mmol·L-1. Parameters measured included seedling growth, active oxygen metabolism, antioxidant enzyme activity, chlorophyll content and photosynthetic fluorescence characteristics. The results showed that: (1) tobacco seedling growth was significantly inhibited under drought stress.(2) Exogenous H2S treatments significantly enhanced both shoot and root fresh weight, increased the total root length, total root surface area, average root diameter and root tip number of tobacco seedlings, enhanced chlorophyll relative content (SPAD), net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), maximal PSⅡ quantum yield (Fv/Fm), PSⅡ actual photochemical efficiency(ΦPSⅡ) and photochemical quenching coefficient (qP), and reduced intercellular carbon dioxide concentration (Ci) and non photochemical quenching coefficient (NPQ), enhanced the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and decreased malondialdehyde (MDA) content and superoxide anion (O2-·) generation rate under drought stress. Foliar application with 0.20 mmol·L-1 NaHS produced the largest growth promotion effects and drought stress alleviation.(3) Compared with drought stress alone, 0.20 mmol·L-1 NaHS increased shoot and root fresh weight of tobacco seedling by 41.82% and 44.83%, enhanced SPAD, Pn, Fv/Fm, ΦPSⅡ and qP by 62.88%, 246.96%, 8.43%, 23.71% and 10.84%, decreased Ci and NPQ by 25.79% and 22.68% enhanced the activities of SOD, POD and CAT by 50.67%, 140.59% and 71.68%, reduced MDA content and O2-· generation rate by 40.08% and 47.58%, respectively. These results indicated that exogenous H2S positively stimulated tobacco seedlings to capture and convert solar energy, thus promoting seeding photosynthesis and growth, and also enhanced the adaptability of seedlings to drought stress by improving antioxidant capacity and reducing oxidative damage.
keywords:flue cured tobacco seedlings  drought stress  exogenous hydrogen sulfide  antioxidant capacities  photosynthetic characteristics  chlorophyll fluorescence
查看全文  查看/发表评论  下载PDF阅读器
   今日访问:465    总访问量:9693362

版权所有:《西北植物学报》编辑部

技术支持:北京勤云科技有限公司