摘要
叶片是水稻主要的光合器官,适度卷曲有利于保持植株叶片直立而不披垂,增加中、下层叶片透光率,从而改善群体光照条件,是理想株型的重要组成,对水稻高产育种具有重要意义.利用甲基黄酸乙酯(EMS)诱变籼稻恢复系缙恢10号获得了一个遗传稳定的水稻生育后期卷叶突变体lrl1.lrl1的叶片在前期生长正常,从13叶龄开始,上三叶沿中脉向内卷曲,且随着生育期推进,卷曲度增加,在成熟期剑叶、倒二叶和倒三叶的卷曲度分别为73.66%,66.91%和45.81%.与野生型缙恢10号相比,除lrl1的千粒重(21.43 g)显著降低外,其他重要农艺性状均没有显著差异.lrl1的叶片小维管束间的泡状细胞数量减少、形状怪异、排列极不规则,导致小维管束之间的夹角变小,从而引起了其叶片的卷曲.lrl1的上三叶光合色素含量均显著高于野生型.但其功能叶净光合速率等均与野生型没有显著差异.经遗传分析和分子定位,该叶片卷曲受一对隐性核基因控制,位于第9染色体分子标记SWU-1和Ind6之间812 kb的区域.通过基因预测,在该区域共有129个候选基因,对其中3个可能与卷叶相关的基因测序,均未发现它们在lrl1与野生型间存在差异.以泡状细胞变化相关的6个卷叶基因在突变体lrl1中的real-time PCR分析表明,卷叶基因ROC5和RL14的表达明显上调,而ACL1,SRL1以及NAL7被下调,暗示了这些基因可能在同一通路上调控叶片的发育.该基因是一个新发现的基因,而且遗传行为简单,其相应突变体含有许多育种有利的性状,因而研究结果为该基因的克隆和功能研究及高产育种奠定了良好基础.
Leaf is the main photosynthetic organ of rice. Moderate rolling leaf could keep plants upright, increasing transmittance in the lower leaf, then improving the light condition of population, which is important for high-yield breeding. Here, we obtained a late-stage moderate-rolled leaf mutant lrll in rice deriving from the restorer line Jinhuil0 （Oryza sativa L. ssp. indica） treated by ethylmethane sulfonate （EMS）. The leaves of lrll were normal in early development stages. Then, the upper 3 leaves began rolling inward along the vein after thirteen leaf age, and the rolling index increased with the plant development until the heading stage. The rolling index of flag leaf, 2^nd and 3^rd leaf from the top in lrll was 73.66%, 66.91% and 45.81% at maturity stage, respectively. Compared with the wild-type, most of the important agronomic traits in lrll existed no significant difference, only 1000-grains weight （21.43 g） were significantly less than that of the wild type. In mutant Irll, the decreased number, strange shape, and irregular arrangement of bulliform cells made the angles among small vascular bundles become smaller, which might cause the leaf rolling. Chlorophyll a and b, total chlorophyll and carotenoid content were all significantly higher than that of wild type. However, the net photosynthetic rate, stomatal conductance, transpiration rate in the Irll existed no difference with those in wild type. By genetic analysis and gene mapping, the rolled leaf mutant was found to be controlled by a single recessive nuclear gene. And the LRL1 was mapped between SWU-1 and Ind6 on the chromosome 9, physical distance is 812 kb. By candidate gene prediction in the area, there are 129 genes altogether. Through sequencing, three genes possibly related to rolled leaf were found existing no difference between lrll and J10. Real-time PCR analysis of 6 cloned rolled leaf gene related to bulliform cells changes showed that the expression quantity of ACL1, SRL1 and NAL7 were down-regulated significantly, that of ROC5 and RL14 were up-regulated significantly, indicating that the LRL1 might be the same passage for regulating leaf development with these genes. The LRL1 is a new found gene. So these results will be important for further cloning and functional analysis of the gene, especially have important utilization value in rice high-yield breeding because of most advantageous traits to breeding in lrll and its simple genetic behavior.
出处
《科学通报》
EI
CAS
CSCD
北大核心
2015年第32期3133-3143,共11页
Chinese Science Bulletin
基金
高等学校学科创新引智计划(B12006)
重庆市重点实验室能力提升项目(cstc2014pt-sy80001)
重庆市科技攻关计划重大项目(CSTC2012ggC80002)资助
