Overexpression of Prunus DAM6 inhibits growth, represses bud break competency of dormant buds and delays bud outgrowth in apple plants
Overexpression of Prunus DAM6 inhibits growth, represses bud break competency of dormant buds and delays bud outgrowth in apple plants
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DOI：
10.1371/journal.pone.0214788
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发表时间：
2019-04-09
期刊：
影响因子：
3.7
通讯作者：
Tao, Ryutaro
中科院分区：
文献类型：
--
作者：
Yamane, Hisayo;Wada, Masato;Tao, Ryutaro
大多数在温带种植的落叶果树需要基因型依赖的寒冷暴露量来释放休眠和发芽。在日本杏 (Prunus mume) 中，休眠相关的 MADS-box 6 (PmDAM6) 可能会影响寒冷介导的休眠释放和芽的萌发。在本研究中，我们试图通过分析 PmDAM6 过表达的转基因苹果 (Malusspp.) 来阐明 PmDAM6 与休眠调节相关的生物学功能。我们生成了 35S:PmDAM6 系和化学诱导过表达系 35S:PmDAM6-GR。在两个过表达系中，枝条生长均受到抑制，并且观察到提前发芽。此外，PmDAM6 表达抑制休眠期间的发芽能力并延迟发芽。此外，在 35S:PmDAM6 和 35S:PmDAM6-GR 的休眠后期和发芽阶段，PmDAM6 表达增加了脱落酸水平并降低了细胞分裂素含量。我们的分析还表明，在休眠的日本杏芽中，脱落酸水平在休眠期间增加，但随后在休眠释放期间下降，而细胞分裂素含量在休眠的日本杏芽的破芽阶段增加。我们之前发现，在日本杏的休眠释放过程中，PmDAM6 的表达持续下调。在休眠的日本杏芽中，PmDAM6 表达模式分别与脱落酸和细胞分裂素含量的减少和增加同时发生。因此，我们假设 PmDAM6 通过调节休眠芽中脱落酸和细胞分裂素的积累来抑制日本杏休眠和芽萌发阶段的芽萌发能力。
Most deciduous fruit trees cultivated in the temperate zone require a genotype-dependent amounts of chilling exposure for dormancy release and bud break. In Japanese apricot (Prunus mume), DORMANCY-ASSOCIATED MADS-box 6 (PmDAM6) may influence chilling-mediated dormancy release and bud break. In this study, we attempted to elucidate the biological functions of PmDAM6 related to dormancy regulation by analyzing PmDAM6-overexpressing transgenic apple (Malusspp.). We generated 35S:PmDAM6 lines and chemically inducible overexpression lines, 35S:PmDAM6-GR. In both overexpression lines, shoot growth was inhibited and early bud set was observed. In addition, PmDAM6 expression repressed bud break competency during dormancy and delayed bud break. Moreover, PmDAM6 expression increased abscisic acid levels and decreased cytokinins contents during the late dormancy and bud break stages in both 35S:PmDAM6 and 35S:PmDAM6-GR. Our analysis also suggested that abscisic acid levels increased during dormancy but subsequently decreased during dormancy release whereas cytokinins contents increased during the bud break stage in dormant Japanese apricot buds. We previously revealed that PmDAM6 expression is continuously down-regulated during dormancy release toward bud break in Japanese apricot. The PmDAM6 expression pattern was concurrent with a decrease and increase in the abscisic acid and cytokinins contents, respectively, in dormant Japanese apricot buds. Therefore, we hypothesize that PmDAM6 represses the bud break competency during dormancy and bud break stages in Japanese apricot by modulating abscisic acid and cytokinins accumulation in dormant buds.