Hu Yuming, Vandenbussche Filip, Van Der Straeten Dominique
Laboratory of Functional Plant Biology, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium.
Planta. 2017 Mar;245(3):467-489. doi: 10.1007/s00425-017-2651-6. Epub 2017 Feb 10.
This review highlights that the auxin gradient, established by local auxin biosynthesis and transport, can be controlled by ethylene, and steers seedling growth. A better understanding of the mechanisms in Arabidopsis will increase potential applications in crop species. In dark-grown Arabidopsis seedlings, exogenous ethylene treatment triggers an exaggeration of the apical hook, the inhibition of both hypocotyl and root elongation, and radial swelling of the hypocotyl. These features are predominantly based on the differential cell elongation in different cells/tissues mediated by an auxin gradient. Interestingly, the physiological responses regulated by ethylene and auxin crosstalk can be either additive or synergistic, as in primary root and root hair elongation, or antagonistic, as in hypocotyl elongation. This review focuses on the crosstalk of these two hormones at the seedling stage. Before illustrating the crosstalk, ethylene and auxin biosynthesis, metabolism, transport and signaling are briefly discussed.
本综述强调，由局部生长素生物合成和运输建立的生长素梯度可受乙烯调控，并引导幼苗生长。深入了解拟南芥中的机制将增加其在作物物种中的潜在应用。在黑暗中生长的拟南芥幼苗中，外源乙烯处理会导致顶端弯钩过度弯曲、下胚轴和根伸长受到抑制以及下胚轴径向肿胀。这些特征主要基于由生长素梯度介导的不同细胞/组织中的差异细胞伸长。有趣的是，乙烯和生长素相互作用调节的生理反应既可以是相加的，如在初生根和根毛伸长中，也可以是协同的，如在下胚轴伸长中，或者是拮抗的。本综述聚焦于这两种激素在幼苗阶段的相互作用。在阐述这种相互作用之前，先简要讨论一下乙烯和生长素的生物合成、代谢、运输及信号传导。
