转AhCMO基因棉花苗期对干旱胁迫的生理反应

以转AhCMO基因的2个棉花品系L1和L2及其转化受体泗棉3号(SM3)为材料,研究了转AhCMO基因棉花对干旱胁迫的生理反应。试验采用盆栽方式在日光温室中进行,以维持土壤含水量为最大持水量的45%作为干旱处理,以正常供水维持土壤含水量为最大持水量的75%作为对照。结果表明,正常供水条件下转基因品系L1和L2与SM3生长表现一致。但是干旱胁迫下,转基因品系L1和L2的干物质积累量、平均净光合速率以及叶片叶绿素的含量都显著高于SM3;而且L1和L2叶片中甜菜碱含量显著高于SM3,过氧化物酶(POD)和超氧化物歧化酶(SOD)的活性也较SM3显著提高。说明2个转AhCMO基因品系的耐旱性得到明显提高,耐旱性的提高与甜菜碱积累量的增加、POD和SOD活性的增强有关。

Physiological Responses of AhCMO Transgenic Cotton Seedlings to Water-Deficit

Water-deficit treatment was conducted on two AhCMO transgenic cotton lines (L1 and L2) and a non-transgenic cv. Simian 3(SM3) to study the physiological responses in seedling stage of AhCMO transgenic cotton, by using pots filled with fertile soil in a green house. Soil moistures were maintained 45% and 75% of the soil water capacity as the drought-stressed treatment and the non-stressed control, respectively. No obvious morphological or developmental differences existed between the transgenic lines (L1 and L2) and field plants in the absence of drought stress. The contents of glycine betain, activities of antioxidant enzymes (POD and SOD), the biomass, net photosynthesis rates and leaf chlorophyll content of transgenic AhCMO cotton lines (L1 and L2) were observably higher than those of SM3 at 20 d after stress treatment had been applied. It is suggested that the enhanced accumulation of glycine betain and the increase of the activities of antioxidant enzymes (POD and SOD) improved water-deficit tolerance in transgenic cotton plants.