花期前后稻穗水分含量与水通道蛋白基因家族表达关系研究

水稻开花期对水分胁迫非常敏感直接影响到结实率,水分供应主要通过水通道蛋白来完成,为了研究花期稻穗的相对含水量与水通道蛋白基因家族表达关系,探讨了花期前后6 d内稻穗相对含水量和水通道蛋白基因家族表达变化情况。结果表明:稻穗相对含水量呈现出花前最高、开花期当天最低、花后则再出现增加的规律;OsPIPs基因家族中各个基因表达的水平各有不同,其中OsPIP1-1、OsPIP1-2、OsPIP2-1、OsPIP2-4和OsPIP2-7的表达水平较高,而OsPIP2-2、OsPIP2-3和OsPIP2-8这3个基因在花期前后6 d内均没有表达;所有OsTIPs基因均表达,但不同OsTIPs基因表达水平在不同时间点也不同,除了OsTIP1-2和OsTIP3-2的表达量比较低外,其他基因的表达量都非常高;OsNIPs基因家族表达量相对较低,如OsNIP1-2、OsNIP1-4、OsNIP3-2及OsNIP3-3在花期前后均不表达,而OsNIP1-1和OsNIP2-1在开花前后均有表达,并在开花当天表达量较高;OsNIP2-2和OsNIP3-1只在开花当天表达,其他时间点均不表达;OsSIP1-1、OsSIP1-2在花前3 d表达量最大,而OsSIP2-1在开花当天表达量最大,其他时间点略有下降。结果说明,花期前后稻穗内OsTIPs基因家族表达量最大,然后是OsPIPs基因家族,再次是OsSIPs和OsNIPs基因家族,但不同水通道蛋白家族各基因间的表达模式也不同,可能与对水分运输分工差异有关,其中液泡膜水通道蛋白在水稻花期水分运输中的作用可能最大。

The Variation of Relative Water Content and Expression of Aquaporins Genes in Rice Panicle During before and after Flowering

Rice flowering period is very sensitive to water stress and directly effect on setting rate;water sup-plies are affected by aquaporin genes expression and its activities.In order to investigate relationship between the relative water content and the aquaporin genes expression in rice panicle,the genes expression level of aquaporin and the relative water content in rice panicle were studied during the time before and after flowering for 6 days.The results showed that:The relative water content in pancile of rice was highest before flowering,and then lowest in the day of flowering,but after flowering the relative water content increased to highest value;Different OsPIPs showed at different expressional patterns,for example,OsPIP1-1,OsPIP1-2,OsPIP2-1,OsPIP2-4 and OsPIP2-7 displayed high level during these time.However,OsPIP2-2,OsPIP2-3 and OsPIP2-8 did not show any expression throughout the flowering period;All OsTIPs were expressed throughout the flowering period,but there were some differences in the expression level in different time,compared to high expression of others OsTIPs,OsTIP1-2 and OsTIP3-2 kept very lower expression level during these time;The expression of OsNIPs displayed very lower level during these time,for example OsNP1-2,OsNIP1-4,OsNIP3-2 and OsNIP3-3 were not expressed throughout the flowering peri-od,OsNIP1-1 and OsNIP2-1 could express in the whole time,However,OsNIP2-2 and OsNIP3-1 could have a cer-tain amount of expression only in flowering day,rather than in the other times;OsSIP1-1,OsSIP1-2 showed at the high value before the flowering day,while OsSIP2-1 reached its maximum during the flowering day.This experiment results showed that,the highest expression level was OsTIPs,followed by OsPIPs,then were OsSIPs and OsNIPs,but different water channel protein genes showed at different expression pattern during these time,and OsTIPs that dis-played high expression level might be need more tonoplast intrinsic protein activities to keep water supply during the flower time of rice panicle.