小麦TaPLC1基因与耐热的相关性研究

Study on the Relationship between TaPLC1 Gene and Heat Tolerance in Wheat

小麦磷酸肌醇特异性磷脂酶C(phosphoinositide-specific PLC,简称PI-PLC)在小麦抗逆过程中具有重要作用。为研究TaPLC1基因与小麦耐热性的关系,选用热敏感型品种中国春(CS)和耐热型品种TAM107,在一叶一心期用PI-PLC抑制剂U73122处理,在两叶一心期进行40℃热胁迫处理,对小麦植株的部分生理指标(MDA、SOD、叶绿素和可溶性糖含量)及TaPLC1基因的表达模式进行测定。结果表明,在两个品种中,抑制剂处理较未处理的幼苗叶片MDA、SOD及可溶性糖含量均升高,叶绿素含量下降,中国春的变化幅度大于TAM107。TaPLC1基因在两个品种中呈现不同的表达模式,但表达量均在热胁迫30 min达到最大值。随着热处理时间的延长,未经抑制剂处理的TAM107叶片中TaPLC1的表达量变化幅度明显大于处理叶片,抑制剂处理的TAM107对热胁迫响应不显著;而未经抑制剂处理的中国春叶片中TaPLC1的表达量变化幅度与抑制剂处理的叶片差异不显著,均在一定程度上响应热胁迫;未经抑制剂处理的叶片,TAM107中TaPLC1表达量的变化幅度明显大于中国春。热胁迫后,中国春幼苗出现明显萎蔫现象,TAM107轻微萎蔫,停止热胁迫后,全部幼苗萎蔫逐渐恢复,而抑制剂处理的幼苗叶尖开始枯萎变黄,热胁迫处理4 h后第5天表型较为明显,品种之间枯萎变黄程度无明显差异。以上结果说明,抑制TaPLC1基因的表达后,幼苗对热胁迫的敏感性增强,TAM107和中国春的耐热性可能与TaPLC1的表达有关。

Plant phosphoinositide-specific phospholipases C（PI-PLCs） function in several essential plant processes associated with environmental stress.In order to study the function of TaPLC1 on the heat tolerance of wheat,the thermo-sensitive variety Chinese Spring and heat-resistant variety TAM107 were used in this study.At one-leaf stage,seedlings were treated with PI-PLC inhibitor U73122.At two-leaf stage,seedlings were treated at the environment of 40 ℃.Both of the physiological indices（MDA,SOD,chlorophyll and soluble sugar content） and the expression pattern of TaPLC1 gene were measured.The results showed that the contents of MDA,soluble sugar and the activity of SOD in the leaves of the two cultivars were higher than those of the untreated ones,and the chlorophyll content was decreased after the heat treatment.The change in Chinese Spring is larger than that in TAM107.The expression patterns of TaPLC1 in the two varieties were different.The expression of TaPLC1 reached to the maximum when the plants were treated for 30 minutes under heat stress.With the heated time extended,the expression of TaPLC1 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 expression between the untreated and the treated Chinese Spring was not significant,but both of them had a response to the thermal conditions.The expression of TaPLC1 in the TAM107 leaves untreated by the inhibitor changed obviously larger than that of Chinese Spring leaves.After the heat stress,all of Chinese spring seedlings were wilted,and TAM107 were a little wilted.After removal of the stress,the wilt 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 at the 5th day after the heat treatment for 4 hour and there was no significant difference in the degree of withering and yellowing between cultivars.Together,our results indicate that when TaPLC1 was inhibited,the wheat seedlings were more sensitive to heat and the tolerance of TAM107 and Chinese Spring may be related to the expression of TaPLC1 .