水稻成蘖特性及相关氮同化酶活性、基因表达分析

Analysis of tillering characteristics,related-nitrogen assimilation enzyme activity and gene expression in rice

水稻(Oryza sativa L.)分蘖是影响成穗数进而影响水稻产量的重要农艺性状之一,低节位(早发)分蘖比高节位(迟发)分蘖具有更高的单穗产量。以12个具有不同分蘖特性的水稻品种为材料,在对各品种水培条件下分蘖发生动态进行观测分析的基础上,进行了与分蘖相关的铵态氮同化酶活性、基因表达等研究。相关性分析发现,水稻分蘖数与第2、3叶位成蘖率呈显著正相关,而与第1叶位成蘖率无显著相关性。第1叶位成蘖率主要受水稻幼苗铵态氮同化酶活性的正向调控,而生长素和独脚金内酯信号通路相关基因表达对该叶位成蘖率影响不显著。第2、3叶位成糵率受幼苗铵态氮同化酶活性及基因表达的影响相对较弱,而主要受生长素和独脚金内酯信号通路相关基因表达的负调控。此外,水稻秧苗的可溶性糖含量、MOC1等控制蘖芽形成的基因及控制CK合成的基因与水稻第1、2、3叶位成糵率的相关性均不显著,而TB1等调控蘖芽伸长的基因作用更为显著。

Tillering of rice is one of the important agronomic traits that affect the number of panicles and thus the yield of rice.It was found that low-node(early-onset)tillers had higher yield per panicle than high-node(late-onset)tillers.12 rice varieties with differ⁃ent tillering characteristics were used as meterials.Based on the observation of tiller development dynamics under hydroponics condi⁃tions,ammonium nitrogen assimilation enzyme activity and rice tillering-related gene expression were analyzed.Correlation analysis found that the number of tillers was significantly positively correlated with the tillering rate in the second and third leaf positions,but no significant correlation between tiller number and tiller rate at the frist leaf position in rice.The tillering rate at the first leaf position was mainly affected by the ammonium assimilation enzyme activity in rice seedlings,while the expression of genes related to the auxin and monopetalactone signaling pathway did not significantly affect it.The second and third leaf tillering rate were relatively weakly af⁃fected by the seedling ammonium nitrogen assimilation enzyme activity and gene expression,but was mainly negatively regulated by the expression of genes related to the auxin and strigolactone signaling pathways.Besides,the soluble sugar content of rice seedlings,genes such as MOC1 that control tiller bud formation and genes that control CK synthesis were not significantly correlated with the til⁃lering rate in the first,second and third leaf positions,while genes such as TB1 that regulate tiller bud elongation had a more signifi⁃cant effect on it.