Ma Zhihui, Qin Yongtian, Wang Yafei, Zhao Xiaofeng, Zhang Fangfang, Tang Jihua, Fu Zhiyuan
Key Laboratory of Wheat and Maize Crops Science/Collaborative Innovation Center of Henan Grain Crops/College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.
Hebi Academy of Agricultural Sciences, Hebi, 458030, China.
PLoS One. 2015 Dec 2;10(12):e0144050. doi: 10.1371/journal.pone.0144050. eCollection 2015.
A long period of silk viability is critical for a good seed setting rate in maize (Zea mays L.), especially for inbred lines and hybrids with a long interval between anthesis and silking. To explore the molecular mechanism of silk viability and its heterosis, three inbred lines with different silk viability characteristics (Xun928, Lx9801, and Zong3) and their two hybrids (Xun928×Zong3 and Lx9801×Zong3) were analyzed at different developmental stages by a proteomic method. The differentially accumulated proteins were identified by mass spectrometry and classified into metabolism, protein biosynthesis and folding, signal transduction and hormone homeostasis, stress and defense responses, and cellular processes. Proteins involved in nutrient (methionine) and energy (ATP) supply, which support the pollen tube growth in the silk, were important for silk viability and its heterosis. The additive and dominant effects at a single locus, as well as complex epistatic interactions at two or more loci in metabolic pathways, were the primary contributors for mid-parent heterosis of silk viability. Additionally, the proteins involved in the metabolism of anthocyanins, which indirectly negatively regulate local hormone accumulation, were also important for the mid-parent heterosis of silk viability. These results also might imply the developmental dependence of heterosis, because many of the differentially accumulated proteins made distinct contributions to the heterosis of silk viability at specific developmental stages.
较长时期的花丝活力对于玉米（Zea mays L.）获得良好的结实率至关重要，尤其是对于花期与吐丝间隔时间长的自交系和杂交种。为了探究花丝活力及其杂种优势的分子机制，采用蛋白质组学方法对三个具有不同花丝活力特征的自交系（浚928、LX9801和综3）及其两个杂交种（浚928×综3和LX9801×综3）在不同发育阶段进行了分析。通过质谱鉴定差异积累的蛋白质，并将其分为代谢、蛋白质生物合成与折叠、信号转导和激素稳态、应激和防御反应以及细胞过程。参与营养物质（蛋氨酸）和能量（ATP）供应、支持花粉管在花丝中生长的蛋白质，对花丝活力及其杂种优势很重要。单个位点的加性和显性效应，以及代谢途径中两个或更多位点的复杂上位互作，是花丝活力中亲杂种优势的主要贡献因素。此外，参与花青素代谢、间接负调控局部激素积累的蛋白质，对花丝活力的中亲杂种优势也很重要。这些结果也可能暗示杂种优势的发育依赖性，因为许多差异积累的蛋白质在特定发育阶段对花丝活力的杂种优势有不同贡献。
