Enhanced photosynthetic activity in pak choi hybrids is associated with increased grana thylakoids in chloroplasts
Enhanced photosynthetic activity in pak choi hybrids is associated with increased grana thylakoids in chloroplasts
复制标题
小白菜杂交种光合作用活性的增强与叶绿体中基粒类囊体的增加有关
DOI：
10.1111/tpj.14893
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发表时间：
2020-07-11
期刊：
影响因子：
7.2
通讯作者：
Li, Ying
中科院分区：
文献类型：
--
作者：
Liu, Tongkun;Duan, Weike;Li, Ying
Increased photosynthetic activity is closely linked to heterosis in plants, but the underlying molecular mechanisms remain elusive. Pak choi (Brassica rapassp.chinensis) is a widely grown vegetable in Asia, and the most commercial cultivars are F(1)hybrids. Here, the inbred pak choi lines WTC and 2Q, and their reciprocal F(1)hybrids WQ and QW, were used to characterize the increased photosynthetic activity in these hybrids at the physiological, cellular and molecular levels. We found that the hybrids had larger leaves, with more grana thylakoids. Additionally, these hybrids had significantly increased net photosynthetic rates (P-n) under both saturating and low irradiance conditions. These data indicate that the increased photosynthetic activity in pak choi hybrids was associated with an improved photosynthetic mechanism and larger leaves. Next, we obtained genome-wide data using transcriptome and bisulfite sequencing. Gene ontology (GO) analysis showed that the differentially expressed genes among the parents and hybrids were mostly enriched in the 'photosynthesis', 'thylakoid', and 'chloroplast' categories, indicating that the increased number of grana thylakoids contributes to the enhanced photosynthetic capacity in hybrids. Furthermore, we found that the increased number of grana thylakoids was associated with the upregulation oflight-harvesting complex of photosystem II 1(BrLhcb1). Yeast one-hybrid and transient assay showed that theBrLhcb1promoter was directly bound byCIRCADIAN CLOCK ASSOCIATED 1(BrCCA1), resulting in increasedBrLhcb1expression and enhanced carbon fixation in hybrids. Finally, our findings provide new insight into molecular mechanisms underlying enhanced photosynthesis in pak choi hybrids.
