Correlation Of Phosphoinositide-specific Phospholipase C Gene Involved In Heat And Drought Tolerance In Wheat (Triticum Aestivum L.)

Phosphoinositide-specific phospholipase C(PI-PLC),as an important member of the phospholipase family,is involved in the plant’s stress response mechanism.To further investigate the role of PI-PLC in the drought and heat stress,specific primers were designed based on the TaPLC1 gene in the NCBI database.The gene was cloned in the heat-drought tolerant cultivar TAM107 and drought-heat sensitive cultivar Chinese Spring(CS),and the sequences were analyzed.Under heat stress or drought-heat stress,comparing the phenotypic difference and physiological index of wheat seedlings with or without U73122 inhibited,and observe the phenotype and physiology of different resistant cultivars before and after stress.Finally,qRT-PCR was used to determine the expression level of this gene inhibited or no during stress.The results showed as following:1.TaPLC1 was obtained from TAM107 and CS.The size about the sequence is 1500 bp.It is predicted that it is an unstable hydrophilic protein,and its structural prediction shows that it has an X/Y domain and a C2 domain.Phylogenetic tree was constructed.Clustering results showed that monocotyledon PI-PLC is highly homologous.2.The contents of malonaldehyde(MDA),soluble sugar and the activity of superoxide dismutase(SOD)in the leaves of the two cultivars were higher than that of the untreated seedlings,and the chlorophyll content was decreased after the heat treatment.The change in Chinese Spring is larger than that in TAM107.After the heat stress,all of Chinese Spring seedlings were wilting,TAM107 were a little wilted.After removal of the stress,the wilting of all seedlings was gradually restored,while the leaves of the two varieties treated with the inhibitor began to wither and yellow.The phenomenon was more obvious in 5 days after the heat treatment.Together,our results indicated that when TaPLC1 gene was inhibited,the wheat seedlings were more sensitive to heat.3.The expression patterns of TaPLC1 gene in the two wheat varieties were different.The expression of TaPLC1 gene reached to the maximum when the plants were treated for 30 minutes under heat stress.The expression of TaPLC1 gene in the TAM107 leaves changed obviously larger than that of Chinese Spring leaves.With the heated time extended,the expression of TaPLC1 gene in the TAM107 leaves untreated by the inhibitor changed obviously larger than that of the treated leaves.The effect of TAM107 treated by inhibitor on the heat stress was not significant.The changes of TaPLC1 gene expression between the untreated and the treated Chinese Spring was not significant,but both of them had a response to the thermal condition.Together,the tolerance of TAM107 and Chinese Spring may be related to the expression of TaPLC1 gene.4.The results showed that compared with the untreated plants by inhibitor,the MDA content of the middle membrane lipid peroxidation products increased,the SOD activity of the active oxygen scavenger was increased,and the soluble sugar content of osmotic adjustment substances increased,but Chlorophyll content were decreased under drought and heat stress.After the stress,the Chinese Spring seedlings showed obvious wilting phenomenon,TAM107 was slightly wilted.After the abolition of stress,all the wilted seedlings were gradually recovered,and the inhibitor-treated leaves of two cultivars began to wilt and yellow,the phenomenon was obvious after 5 days of stress,while the time of Chinese Spring wilted and yellowed before TAM107,there was no significant difference in the end.This indicated that when the TaPLC1 gene was inhibited,the plants were more sensitive to stress.5.During heat and drought stress treatment,the gene of TaPLC1’s expression in the two cultivars responded rapidly within 15 min and reached the maximum at 30 min.The expression level in TAM107 was much higher than that in Chinese Spring,and when the seedlings treated with inhibitor,the gene of TaPLC1’s expression in the two cultivars were all lower than untreated,but also had the tendency to respond to stress.The above results indicate the heat-drought resistance of TAM107 and Chinese Spring may be related to the expression of TaPLC1 gene.