转MsLEA4-4基因拟南芥株系的耐盐性分析

为了深入研究紫花苜蓿（Medicago sativa）MsLEA4-4基因的抗逆性，本试验对前期获得的转MsLEA4-4基因的拟南芥（Arabidopsis thaliana）株系进行不同浓度盐胁迫处理，以验证MsLEA4-4基因在拟南芥植株体内的耐盐性。试验结果表明：盐胁迫后转基因株系的发芽率达到55%，比对照植株（Control plant，CK）高81%；转基因株系的鲜重、叶绿素含量均高于CK（P<0.05）；盐胁迫后转基因株系的存活率比CK提高75.0%~81.3%；盐胁迫明显抑制根系生长，但转基因植株的侧根数量比CK多4~5根（P<0.05）；盐胁迫后转基因株系体内的可溶性糖含量（P<0.05）和超氧化物歧化酶（P<0.01），过氧化氢酶（P<0.01），过氧化物酶（P<0.05）活性均高于CK，脯氨酸（P<0.01）和丙二醛（P<0.05）含量均低于CK。综上可得，MsLEA4-4基因参与了拟南芥体内的耐盐性调控，提高了转基因拟南芥对盐胁迫的耐受性。本研究为进一步探索MsLEA4-4在转基因紫花苜蓿盐胁迫中的功能及培育耐盐性紫花苜蓿品种提供依据。

Characterization of the Salt Tolerance of Transgenic Arabidopsis Thaliana Overexpression of MsLEA4-4 from Medicago Sativa

In order to further analyze the function of MsLEA4-4 in stress resistance,different level of salt stress was applied on Arabidopsis thaliana transgenic lines to verify its salt tolerance function. MsLEA4-4 overexpression transgenic lines were used in this study. The results showed that under salt stress the germination rate of transgenic lines was reached to 55%,which was 81% higher than that of control plant (CK). The fresh weight and chlorophyll content of transgenic lines were higher than CK (P<0.05). The survival rate of transgenic lines were increased by 75.0%~81.3% compared to CK. Salt stress significantly inhibited root growth,but the number of lateral roots of transgenic plants was 4~5 more than that of CK (P<0.05);the content of soluble sugar (P<0.05),SOD (P<0.01),CAT (P<0.01) and POD (P<0.05) activity in transgenic lines was higher than that of CK under salt stress. However,the content of proline (P<0.01) and malondialdehyde (P<0.05) was lower than that of CK. We speculated that MsLEA4-4 was involved in the regulation of salt stress in Arabidopsis thaliana,which improved the tolerance of transgenic lines to salt stress. The study provides a basis for further exploring the function of MsLEA4-4 in transgenic alfalfa under salt stress,and provides a basis for the cultivation of salt-tolerant alfalfa.