College of Life Sciences, Nanjing Normal University, Nanjing 210023, China.
Plant Cell Physiol. 2021 Mar 25;62(1):3-7. doi: 10.1093/pcp/pcaa134.
Plants possess a regeneration capacity that enables them to survive after wounding. For example, detached Arabidopsis thaliana leaves are able to form adventitious roots from their cutting sites even in the absence of exogenous hormone supplements, as process termed de novo root regeneration (DNRR). Wounding rapidly induces auxin biosynthesis at the cutting sites and then elicits a signaling cascade to promote cell fate transitions and finally generate the adventitious roots. However, rooting rates in older plants are much lower than in younger leaf explants. In this review, we highlight the recent breakthroughs in the understanding of DNRR decay in older plants from at least two independent signaling routes: (i) via the accumulation of EIN3 protein in older plants, which directly suppresses expression of WUSCHEL RELATED HOMEOBOX (WOX) genes to inhibit rooting; (ii) the miR156-SPLs-AP2/ERFs pathway, which modulates root regeneration by reducing auxin biosynthesis.
植物具有再生能力，使它们在受伤后能够存活。例如，拟南芥离体叶片即使在外源激素补充物不存在的情况下，也能够从其切割部位形成不定根，这一过程被称为从头再生根（DNRR）。受伤会迅速在切割部位诱导生长素的生物合成，然后引发信号级联反应，以促进细胞命运的转变，并最终产生不定根。然而，在较老的植物中生根率要比年轻的叶片外植体低得多。在这篇综述中，我们强调了从至少两条独立的信号通路理解较老植物 DNRR 衰退的最新突破：（i）通过在较老的植物中 EIN3 蛋白的积累，它直接抑制 WUSCHEL RELATED HOMEOBOX（WOX）基因的表达，从而抑制生根；（ii）miR156-SPLs-AP2/ERFs 途径通过减少生长素的生物合成来调节根再生。
