盆栽干旱条件下玉米材料的干旱耐受性鉴定及胁迫响应基因的表达研究

Study on Identification of Soil Drought Tolerance of Multiple Maize Materials,and Expression of Stress-Responsive Genes in Maize under Pot Soil Drought

玉米抗旱性状和表型极为复杂多样,主要涉及到根系生长。因此,鉴定根的生长表型非常必要。但是,玉米根系与耐旱性之间相关性仍然不明确。此外,干旱会引起两种类型的细胞变化(创伤/损伤和细胞膜稳定性)。目前,人们对这两组基因的表达与玉米中抗旱表型之间的关联了解甚少。本研究在土壤相对含水量为32.0%的温室盆栽条件下对抽雄前六叶期的28种具有温带和热带种质的玉米材料(包括26个玉米优良自交系和2个杂种)的表型(地上和地下部分)进行了鉴定,并且对一个创伤/损伤诱导蛋白和一个疏水蛋白基因的表达进行了分析。结果表明,根的长度和密度(轴根和次生侧根)的确与玉米的耐旱性有关,然而,并非所有玉米材料根长都会在干旱条件下显著增加。创伤/损伤诱导蛋白基因和膜疏水蛋白的基因在叶片中的高表达和在根部中的低表达可能有助于增强玉米的抗旱能力。

The drought resistant traits and phenotypes of maize are extremely complex and diverse,mainly involving root system growth.Therefore,it is very necessary to characterize root growth.However,the existing conclusions on the correlation between roots and drought tolerance in maize are still ambiguous.In addition,drought can lead to two types of cellular damage(wound/damage and cell membrane stability),and at present,the association between expression of these two groups of the genes and the drought resistant phenotype in maize is yet poorly understood.In this study,under pot conditions in a greenhouse where the relative water content of pot soil was 32.0%,the phenotypes of aboveground parts and roots of 28 temperate and tropical germplasms maize materials including 26 maize inbred lines and 2 hybrids at the six-leaf stage before tasselling were characterized.The expression of one wound-inducible protein gene and one hydrophobic protein gene under drought was analyzed.Consequently,the length and density of roots(axes roots and second-order laterals)under drought were indeed associated with the drought tolerance of maize,but the increased length of roots was not an inevitable result for all maize materials under soil drought.The high expression of the wound-inducible protein and hydrophobic protein genes in the leaves and the low expression in the roots may help to enhance the drought resistance of maize.