Competition between anthocyanin and kaempferol glycosides biosynthesis affects pollen tube growth and seed set of Malus

作者：Weifeng Chen, Zhengcao Xiao, Yule Wang, Jinxiao Wang, Rui Zhai, Kui Lin‐Wang, Richard V. Espley, Fengwang Ma, Pengmin Li · 发表于：Horticulture Research · 年份：2021 · DOI：10.1038/s41438-021-00609-9 · 被引用次数：67 · 研究领域：Plant Gene Expression Analysis、Plant biochemistry and biosynthesis、Plant Molecular Biology Research

Flavonoids play important roles in regulating plant growth and development. In this study, three kaempferol 3-O-glycosides were identified and mainly accumulated in flowers but not in leaves or fruits of Malus. In Malus, flower petal color is normally white, but some genotypes have red flowers containing anthocyanin. Anthocyanin biosynthesis appears to be in competition with kaempferol 3-O-glycosides production and controlled by the biosynthetic genes. The white flower Malus genotypes had better-developed seeds than the red flower genotypes. In flowers, the overexpression of MYB10 in Malus domestica enhanced the accumulation of anthocyanin, but decreased that of kaempferol 3-O-glycosides. After pollination the transgenic plants showed slower pollen tube growth and fewer developed seeds. Exogenous application of different flavonoid compounds suggested that kaempferol 3-O-glycosides, especially kaempferol 3-O-rhamnoside, regulated pollen tube growth and seed set rather than cyanidin or quercetin 3-O-glycosides. It was found that kaempferol 3-O-rhamnoside might regulate pollen tube growth through effects on auxin, the Rho of plants (ROP) GTPases, calcium and the phosphoinositides signaling pathway. With the inhibition of auxin transport, the transcription levels of Heat Shock Proteins (HSPs) and ROP GTPases were downregulated while the levels were not changed or even enhanced when blocking calcium signaling, suggesting that HSPs and ROP GTPases were downstream of auxin signaling...