Abstract:The experiment cloned an E3 ubiquitin ligase gene LeRma1(GenBank accession No XM_004243764.1)by RT-PCR method with tomato ‘Hadafen 801’ used as experimental materials.To provide a theoretical basis for the cultivation and improved varieties of tomato,we analyzed the gene sequence,while studied the expression and physiological characteristics of LeRma1 gene in different parts of the tomato plants under abiotic stress(drought,salt,alkali,high temperature,low temperature).The results showed that:(1)LeRma1 gene sequence analysis showed that the length of LeRma1 gene was 729 bp,which encoded 242 amino acids.It was predicted that the molecular mass of its protein was 27.05 kD,and pI was 7.97.Homology analysis showed that the deduced amino acid sequence exhibited high homology with Solanum tuberosum(91% similarity).(2)RT-PCR results indicating that the gene were expressed in roots,stems,leaves,flowers and fruits of tomato,and the changes in expression levels were not significantly different.(3)Expression of LeRma1 had the advantage in leaves,and the changes in expression levels were not significantly different in roots under the whole drought stress.The other drought-related genes DREB2A,LEA,ABI3 are all expression in leaves,and they were enhanced expression compared with the control,while DREB2A,ABI3 have not detected in roots under the whole drought stress.(4)Major membrane lipid peroxidation product of MDA content was increased significantly,and plasma membrane systems were severely damaged,the protective enzyme activity increased significantly,and activity in roots was significantly higher than that in leaves.(5)LeRma1 gene was enhanced expression in roots and leaves of tomato,and the gene in the leaves all starting enhanced expression after stress 3 h under abiotic stress(salt,alkali,high temperature,low temperature).The results showed that LeRma1 was the gene of enhancement expression by drought-induced and it had the advantage in leaves.It showed that there were some differences that the function of the LeRma1 genes in different tissues(organizational differences)under drought stress,and LeRma1 genes may be participate response of drought stress tolerance and the signal transduction process,it also might play an important role in the tomato under the other abiotic stresses.