Kim Yeon-Ok, Kang Hunseung
a Department of Plant Biotechnology, College of Agriculture and Life Sciences , Chonnam National University , Buk-gu , Gwangju , Korea.
Biosci Biotechnol Biochem. 2018 Sep;82(9):1656-1665. doi: 10.1080/09168451.2018.1486177. Epub 2018 Jun 18.
To get insights into the functions of metallothionein (MT) in plant response to multiple stresses, expressions of 10 rice MT genes (OsMTs) and 7 Arabidopsis MT genes (AtMTs) were comprehensively analyzed under combined heavy metal and salt stress. OsMT1a, OsMT1b, OsMT1c, OsMT1g, and OsMT2a were increased by different heavy metals. Notably, ABA remarkably increased OsMT4 up to 80-fold. Combined salt and heavy metals (Cd, Pb, Cu) synergistically increased OsMT1a, OsMT1c, and OsMT1g, whereas combined salt and HO or ABA synergistically increased OsMT1a and OsMT4. Heavy metals decreased AtMT1c, AtMT2b, and AtMT3 but cold or ABA increased AtMT1a, AtMT1c, and AtMT2a. AtMT4a was markedly increased by salt stress. Combined salt and other stresses (Pb, Cd, HO) synergistically increased AtMT4a. Taken together, these findings suggest that MTs in monocot and dicot respond differently to combined stresses, which provides a valuable basis to further determine the roles of MTs in broad stress tolerance.
为深入了解金属硫蛋白（MT）在植物应对多种胁迫中的功能，我们对10个水稻MT基因（OsMTs）和7个拟南芥MT基因（AtMTs）在重金属和盐联合胁迫下的表达进行了全面分析。不同的重金属可使OsMT1a、OsMT1b、OsMT1c、OsMT1g和OsMT2a的表达增加。值得注意的是，脱落酸（ABA）可使OsMT4的表达显著增加高达80倍。盐与重金属（镉、铅、铜）联合作用可协同增加OsMT1a、OsMT1c和OsMT1g的表达，而盐与过氧化氢（HO）或ABA联合作用则可协同增加OsMT1a和OsMT4的表达。重金属可使AtMT1c、AtMT2b和AtMT3的表达降低，但低温或ABA可使AtMT1a、AtMT1c和AtMT2a的表达增加。盐胁迫可使AtMT4a的表达显著增加。盐与其他胁迫（铅、镉、HO）联合作用可协同增加AtMT4a的表达。综上所述，这些发现表明单子叶植物和双子叶植物中的MT对联合胁迫的反应不同，这为进一步确定MT在广泛的胁迫耐受性中的作用提供了有价值的基础。
