【摘要】 以贵州地方稻种来拢突变体库中能稳定遗传的小圆粒半矮秆突变体srd-1为材料,对其半矮化和小圆粒性状分子机制进行研究。暗形态建成表明srd-1突变体矮化性状与BR无关。srd-1突变体表现对GA敏感,外源GA3对突变体幼苗第2叶鞘有促进生长作用,能诱导α-淀粉酶活性,可以使倾斜方向排列的细胞微管骨架恢复至野生型横向排列方向,表明srd-1突变体矮化性状与GA信号传导途径无关。GA合成途径中关键酶基因Os KS1和Os GA2ox1表达相对于野生型差异不显著,Os CPS、Os KO2、Os KAO、Os GA20ox2和Os GA3ox2基因表达下调,初步说明srd-1突变体的矮化性状可能是由活性GA生物合成降低所致。此外,小圆粒调控基因SRS1、SRS3和SRS5表达下调,表明srd-1突变体突变基因同时参与了籽粒大小和株高的调控,突变基因影响了活性GA的生物合成和小圆粒调控关键酶基因的表达,进而导致了矮化和小圆粒表型的产生。该研究为突变体突变基因的定位及利用研究提供了参考。更多还原

【Abstract】 In this paper,the mutant library was built from a Guizhou native rice variety ‘Lailong’using EMS treatment,from which the small round seed and semi-dwarfism characteristics of mutant srd-1 was identified,and the molecular mechanism of small round seed and semi-dwarf traits were studied. The skotomorphogenesis showed that the dwarf trait of srd-1 mutant was not related to the BR. srd-1 mutant performance was sensitive to GA. Exogenous GA \-3 could promote the growth of seedling’s second leaf sheath of srd-1,induce the activity of α- amylase and rescue the tilt arrangement of cell microtubules skeleton back to wild type transverse arrangement,which indicated that the dwarf character was not related to GA signal transduction pathway. The expressions of key enzyme genes Os KS1 and Os GA2ox1 in GA synthesis pathway had no significant differences compared with wild type,but the gene expressions Os CPS、Os KO2、Os KAO、Os GA20ox2 and Os GA3ox2 were down-regulated,which preliminarily indicated that the dwarf trait of srd-1 mutant might be due to the activity decrease of GA biosynthesis. In addition,the expressions of small round seed control genes SRS1、SRS3 and SRS5 exhibited down-regulated. This suggested that the mutant gene of srd-1 mutant simultaneously involved in the regulation of grain size and plant height,affected activity GA biosynthesis and the expressions of small round seed key enzyme regulated genes,and then led tothe dwarf and small round seed phenotype. The study provided a reference for the mutant gene mapping and using research.更多还原