Comparative proteomics of the superior and inferior spikelets at the early grain filling stage in rice cultivars contrast for panicle compactness and ethylene evolution
Comparative proteomics of the superior and inferior spikelets at the early grain filling stage in rice cultivars contrast for panicle compactness and ethylene evolution
复制标题
DOI：
10.1016/j.jplph.2016.07.008
复制
发表时间：
2016-09-01
影响因子：
4.3
通讯作者：
Shaw, Birendra P.
中科院分区：
文献类型：
--
作者：
Das, Kaushik;Panda, Binay B.;Shaw, Birendra P.
在水稻育种中，以增加每穗颖花数为目标的育种方案一直伴随着大穗型水稻弱势颖花灌浆不良，导致产量不利。本研究试图通过比较蛋白质组学的方法来了解弱势和上级小穗差异灌浆的原因，考虑紧凑穗型水稻品种Mahalaxmi和疏松穗型水稻品种Upahar，这两个品种分别表现出较差和良好的籽粒灌浆。对两个水稻品种的穗部紧凑度和籽粒充实度的初步研究表明，这两个参数之间呈负相关。进一步观察到Mahalaxmi的穗紧密度与上级和下级小穗的乙烯释放量较高相关，与松散穗Upahar相比。蛋白质组学研究表明，Mahalaxmi的上级和下级小穗差异表达的21个蛋白质，也表达在Upahar。而在Upahar中，只有2个蛋白质在上级和下级小穗间差异表达，表明Mahalaxmi和Upahar中位于穗上上级和下级位置的小穗的代谢活性存在很大差异。与Mahalaxmi中的上级小穗相比，在下位小穗中下调的蛋白质中有importin-α、延伸因子1-β和细胞分裂控制蛋白48，它们对细胞周期进程和细胞分裂是必需的。这些蛋白质的低表达可能会抑制胚乳细胞分裂的弱势小穗，限制他们的库容量，并导致穷人灌浆相比，在上级小穗。Mahalaxmi的籽粒灌浆不良也可能是弱势小穗中乙烯高度进化的结果，这反映在观察到该品种的弱势小穗中S-腺苷甲硫氨酸合酶及其编码基因的表达显著高于上级小穗，而Upahar则没有; S-腺苷甲硫氨酸合酶催化S-腺苷甲硫氨酸的合成，S-腺苷甲硫氨酸是乙烯生物合成的前体。(C)2016 Elsevier GmbH. All rights reserved.
The breeding programmes in rice aimed at increasing the number of spikelets per panicle have been accompanied by poor grain filling in the inferior spikelets of large panicle rice, leading to yield disadvantage. The present study attempted to understand the reason for differential grain filling in the inferior and superior spikelets by comparative proteomics considering a compact-panicle rice cultivar Mahalaxmi and a lax-panicle rice cultivar Upahar, which show poor and good grain filling, respectively. An initial study of two rice cultivars for panicle compactness and grain filling revealed an inverse correlation between the two parameters. It was further observed that the panicle compactness in Mahalaxmi was associated with a higher evolution of ethylene by the spikelets, both superior and inferior, compared with the lax-panicle Upahar. The proteomic studies revealed that the superior and inferior spikelets of Mahalaxmi differentially expressed 21 proteins that were also expressed in Upahar. However, in Upahar, only two of these proteins were differentially expressed between the superior and inferior spikelets, indicating that the metabolic activities of the spikelets occupying the superior and inferior positions on the panicle were very different in Mahalaxmi compared with those in Upahar. Among the proteins that were downregulated in the inferior spikelets compared with the superior ones in Mahalaxmi were importin-alpha, elongation factor 1-beta and cell division control protein 48, which are essential for cell cycle progression and cell division. Low expression of these proteins might inhibit endosperm cell division in the inferior spikelets, limiting their sink capacity and leading to poor grain filling compared to that in the superior spikelets. The poor grain filling in Mahalaxmi may also be a result of the high evolution of ethylene in the inferior spikelets, which is reflected from the observation that these spikelets showed significantly higher expression of S-adenosylmethionine synthase and the gene encoding the enzyme than the superior spikelets in this cultivar, but not in Upahar; S-adenosynlmethionine synthase catalyses the synthesis of S-adenosylmethionine, the precursor of ethylene biosynthesis. (C) 2016 Elsevier GmbH. All rights reserved.