矮秆基因Rht_NM9在小麦株高建成中对内源激素含量的影响

Effects of Dwarf Gene Rht_NM9 on Contents of Endogenous Hormone Regulating Plant Height of Common Wheat

普通小麦品种"南农9918"经甲基磺酸乙酯(ethyl methanesulfonate,EMS)诱变获得一个矮秆、多蘖、长穗突变体"NM9",在该突变体中定位到一个新的矮秆突变基因Rht_NM9。内源激素在普通小麦株高建成的过程中发挥重要的调节作用,为了解析Rht_NM9致矮的生理机制,本研究以南农9918及其矮秆突变体NM9为材料,利用酶联免疫吸附分析法(enzyme-linked immunosorbent assays,ELISA)测定了不同生育期各节间内源赤霉素(GA)、生长素(IAA)、脱落酸(ABA)和玉米素核苷(ZR)的含量,分析小麦发育关键时期的内源激素含量变化与株高的关系。结果表明,在孕穗期和抽穗期,矮秆突变体NM9中GA、ABA含量均显著高于南农9918,而ZR含量则显著低于南农9918,IAA含量在南农9918和突变体NM9之间无明显差异。此外,突变体NM9各节间中GA/ABA比值显著高于南农9918,而IAA/ABA、(IAA+GA)/ABA、ZR/ABA比值显著低于南农9918。以上结果表明小麦株高受多种激素调控,突变体中内源ABA含量升高,IAA/ABA和ZR/ABA比值降低会抑制植物株高伸长。

A dwarf wheat mutant(NM9)with additional tillers and elongated spikes was obtained by treating NAU9918seeds with ethyl methanesulfonate(EMS).The decreased plant height in NM9was controlled by a novel dwarf gene Rht_NM9.The endogenous plant hormones play important roles in regulating plant height of common wheat.To understand the dwarfing mechanism of Rht_NM9and the relationship between endogenous hormone contents and plant height,measured contents of endogenous gibberellic acid(GA),auxin(IAA),abscisic acid(ABA)and zeatin riboside(ZR)in internodes of NM9and NAU9918at different stages by enzyme-linked immunosorbent assays(ELISA).Our study indicated that contents of GA and ABA in NM9were significantly higher than there in NAU9918,and ZR content in NM9was significantly lower than that in NAU9918at both booting and heading stages.Nevertheless,no difference of IAA content was observed between the mutant and the wild-type.In addition,the GA/ABA ratio in internodes of the mutant was significantly higher than that of the wild-type,however,the ratios of IAA/ABA,(IAA+GA)/ABA and ZR/ABA were significantly lower than there of the wild-type.All these results indicated that plant height in wheat was regulated by multiple hormones.Plant height would be inhibited with increasing content of endogenous ABA and decreasing ratios of IAA/ABA and ZR/ABA in wheat.