Rice Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350019, Fujian, China.
Key Laboratory of Germplasm Innovation and Molecular Breeding of Hybrid Rice for South China, Ministry of Agriculture and Rural Affairs, Fuzhou, 350003, Fujian, China.
BMC Plant Biol. 2020 Feb 14;20(1):76. doi: 10.1186/s12870-020-2277-x.
Rice ratooning has traditionally been an important component of the rice cropping system in China. However, compared with the rice of the first harvest, few studies on factors effecting ratoon rice yield have been conducted. Because ratoon rice is a one-season rice cultivated using axillary buds that germinate on rice stakes and generate panicles after the first crop's harvest, its production is mainly affected by the growth of axillary buds. The objectives of this study were to evaluate the sprouting mechanism of axillary buds to improve the ratoon rice yield.
First, we observed the differentiation and growth dynamics of axillary buds at different nodes of Shanyou 63, and found that they differentiated from bottom to top before the heading of the mother stem, and that they developed very slowly. After heading they differentiated from top to bottom, and the ones on the top, especially the top 2nd node, developed much faster than those at the other nodes. The average length and dry weight of the axillary buds were significantly greater than those at other nodes by the yellow ripe stage, and they differentiated into pistils and stamens by 6 d after the yellow ripe stage. The morphology of vegetative organs from regenerated tillers of Shanyou 63 also suggested the superior growth of the upper buds, which was regulated by hormones, in ratoon rice. Furthermore, a comprehensive proteome map of the rice axillary buds at the top 2nd node before and after the yellow ripe stage was established, and some proteins involved in steroid biosynthesis were significantly increased. Of these, four took part in brassinosteroid (BR) biosynthesis. Thus, BR signaling may play a role in the germination of axillary buds of ratoon rice.
The data provide insights into the molecular mechanisms underlying BR signaling, and may allow researchers to explore further the biological functions of endogenous BRs in the germination of axillary buds of ratoon rice.
在中国，水稻再生稻一直是水稻种植系统的重要组成部分。然而，与第一季水稻相比，对影响再生稻产量的因素的研究较少。因为再生稻是一种一季稻，利用在第一季作物收获后从稻桩上萌发的腋芽进行栽培，其产量主要受腋芽生长的影响。本研究旨在评价腋芽萌发机制，以提高再生稻产量。
首先，我们观察了汕优 63 不同节位腋芽的分化和生长动态，发现它们在母茎抽穗前从下到上分化，生长非常缓慢。抽穗后，它们从上到下分化，顶部，尤其是顶部第 2 节位的腋芽发育得更快。到黄熟期，腋芽的平均长度和干重显著大于其他节位，并且在黄熟期后 6 天分化成雌蕊和雄蕊。汕优 63 再生分蘖的营养器官形态也表明，在再生稻中，上部腋芽在激素调节下具有优越的生长。此外，还建立了黄熟期前后顶部第 2 节位水稻腋芽的综合蛋白质组图谱，发现一些参与甾体生物合成的蛋白质显著增加。其中，有 4 种参与油菜素内酯（BR）生物合成。因此，BR 信号可能在再生稻腋芽萌发中起作用。
该数据提供了对 BR 信号转导分子机制的深入了解，可能使研究人员进一步探索内源性 BR 在再生稻腋芽萌发中的生物学功能。
