Laboratorio de Bioquímica Vegetal, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile; Programa Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Universidad de Chile, Santiago, Chile.
Laboratorio de Bioquímica Vegetal, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile.
J Plant Physiol. 2019 Mar-Apr;234-235:1-8. doi: 10.1016/j.jplph.2019.01.004. Epub 2019 Jan 4.
In grapevine (Vitis vinifera L.) buds, the short day (SD)-photoperiod induces endodormancy and increases the level of ABA and the expression of ABA key biosynthesis genes, which suggests that ABA could be the mediator of the photoperiodic induction of endodormancy. In the present study, it was established that during the development of the endodormancy, the content of ABA and the accumulation of starch increased in parallel in the buds; however, these increases occurred after the buds were already in the state of endodormancy. Despite this finding the exogenous applications of ABA to single-bud cuttings increased the starch content and up-regulated the expression of starch synthesis genes (VvSS1 and VvSS3) and down-regulated the expression of sucrose metabolism genes, invertase (VvINV) and sucrose phosphate synthase (VvSUPS). In addition, the manipulation of the endogenous content of ABA in the grapevine buds by applications of hydrogen cyanamide and uniconazole-P, revealed that the depth of the endodormancy depends on the ABA levels. Taken together, the results indicate that the development of the endodormancy in grapevine buds is associated with the accumulation of starch and a shift in metabolism towards a storage metabolism; as ABA stimulates both processes, it must play an important role in the maintenance and release but not the induction of endodormancy in grapevine buds.
在葡萄（Vitis vinifera L.）芽中，短日照（SD）诱导了内休眠，并增加了 ABA 的水平和 ABA 关键生物合成基因的表达，这表明 ABA 可能是光周期诱导内休眠的介质。在本研究中，确定在休眠发育过程中，芽中的 ABA 含量和淀粉积累呈平行增加；然而，这些增加发生在芽已经处于内休眠状态之后。尽管有这一发现，外源施用 ABA 到单芽插条增加了淀粉含量，并上调了淀粉合成基因（VvSS1 和 VvSS3）的表达，下调了蔗糖代谢基因、转化酶（VvINV）和蔗糖磷酸合酶（VvSUPS）的表达。此外，通过施用氰胺和烯效唑-P 来操纵葡萄芽内的内源 ABA 含量，表明内休眠的深度取决于 ABA 水平。总之，结果表明，葡萄芽内休眠的发展与淀粉的积累和代谢向储存代谢的转变有关；由于 ABA 刺激这两个过程，它在内休眠的维持和释放中必须发挥重要作用，但不是诱导作用。
