Tsyganov V E, Voroshilova V A, Priefer U B, Borisov A Y, Tikhonovich I A
All-Russia Research Institute for Agricultural Microbiology, Laboratory of Genetics of Plant-Microbe Interactions, St-Petersburg, Pushkin.
Ann Bot. 2002 Apr;89(4):357-66. doi: 10.1093/aob/mcf051.
Twelve non-nodulating pea (Pisum sativum L.) mutants were studied to identify the blocks in nodule tissue development. In nine, the reason for the lack of infection thread (IT) development was studied; this had been characterized previously in the other three mutants. With respect to IT development, mutants in gene sym7 are interrupted at the stage of colonization of the pocket in the curled root hair (Crh- phenotype), mutants in genes sym37 and sym38 are blocked at the stage of IT growth in the root hair cell (Ith- phenotype) and mutants in gene sym34 at the stage of IT growth inside root cortex cells (Itr- phenotype). With respect to nodule tissue development, mutants in genes sym7, sym14 and sym35 were shown to be blocked at the stage of cortical cell divisions (Ccd- phenotype), mutants in gene sym34 are halted at the stage of nodule primordium (NP) development (Npd- phenotype) and mutants in genes sym37 and sym38 are arrested at the stage of nodule meristem development (Nmd- phenotype). Thus, the sequential functioning of the genes Sym37, Sym38 and the gene Sym34 apparently differs in the infection process and during nodule tissue development. Based on these data, a scheme is suggested for the sequential functioning of early pea symbiotic genes in the two developmental processes: infection and nodule tissue formation.
研究了12个不结瘤豌豆(Pisum sativum L.)突变体,以确定根瘤组织发育中的阻断环节。对其中9个突变体研究了缺乏感染丝(IT)发育的原因;另外3个突变体的这一情况先前已有描述。关于IT发育,sym7基因的突变体在卷曲根毛(Crh-表型)中口袋状结构的定殖阶段被阻断,sym37和sym38基因的突变体在根毛细胞中IT生长阶段被阻断(Ith-表型),sym34基因的突变体在根皮层细胞内IT生长阶段被阻断(Itr-表型)。关于根瘤组织发育,sym7、sym14和sym35基因的突变体在皮层细胞分裂阶段被阻断(Ccd-表型),sym34基因的突变体在根瘤原基(NP)发育阶段停滞(Npd-表型),sym37和sym38基因的突变体在根瘤分生组织发育阶段停滞(Nmd-表型)。因此,Sym37、Sym38基因和Sym34基因在感染过程和根瘤组织发育过程中的顺序功能显然不同。基于这些数据,提出了一个早期豌豆共生基因在感染和根瘤组织形成这两个发育过程中顺序功能的示意图。