Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA.
J Exp Bot. 2010 Jun;61(11):3137-49. doi: 10.1093/jxb/erq139. Epub 2010 Jun 4.
Timing of various developmental stages including anthesis and whole-plant ('monocarpic') senescence influences yield and quality of annual crops. While a correlation between flowering/seed filling and whole-plant senescence has been observed in many annuals, it is unclear how the gene networks controlling these processes interact. Using near-isogenic germplasm, it has previously been demonstrated that a grain protein content (GPC) locus on barley chromosome 6 strongly influences the timing of post-anthesis flag leaf senescence, with high-GPC germplasm senescing early. Here, it is shown that the presence of high-GPC allele(s) at this locus also accelerates pre-anthesis plant development. While floral transition at the shoot apical meristem (SAM; determined by the presence of double ridges) occurred simultaneously, subsequent development was faster in the high- than in the low-GPC line, and anthesis occurred on average 5 d earlier. Similarly, sequential (pre-anthesis) leaf senescence was slightly accelerated, but only after differences in SAM development became visible. Leaf expression levels of four candidate genes (from a list of genes differentially regulated in post-anthesis flag leaves) were much higher in the high-GPC line even before faster development of the SAM became visible. One of these genes may be a functional homologue of Arabidopsis glycine-rich RNA-binding protein 7, which has previously been implicated in the promotion of flowering. Together, the data establish that the GPC locus influences pre- and post-anthesis barley development and senescence, and set the stage for a more detailed analysis of the interactions between the molecular networks controlling these important life history traits.
各个发育阶段的时间安排，包括开花和整株（“单生”）衰老，都会影响一年生作物的产量和品质。虽然许多一年生植物中观察到开花/种子填充和整株衰老之间存在相关性，但控制这些过程的基因网络如何相互作用尚不清楚。使用近等基因系，先前已经证明大麦 6 号染色体上的一个籽粒蛋白质含量（GPC）位点强烈影响花后旗叶衰老的时间，高 GPC 种质衰老较早。在这里，表明该位点的高 GPC 等位基因（s）的存在也加速了花前植物发育。虽然茎尖分生组织（SAM；由双脊的存在决定）的花转变同时发生，但在高 GPC 系中随后的发育更快，开花平均早 5 天。同样，顺序（花前）叶片衰老略有加速，但仅在 SAM 发育的差异变得明显之后。四个候选基因（来自花后旗叶差异调节基因列表）的叶片表达水平在高 GPC 系中甚至在 SAM 更快发育变得明显之前就更高。其中一个基因可能是拟南芥富含甘氨酸的 RNA 结合蛋白 7 的功能同源物，该基因先前与促进开花有关。总之，这些数据表明 GPC 位点影响大麦的花前和花后发育和衰老，并为更详细地分析控制这些重要生活史特征的分子网络之间的相互作用奠定了基础。
