ICAR-National Institute for Plant Biotechnology, New Delhi, 110012, India.
Department of Biosciences, Durham University, Durham, DH1 3LE, UK.
Planta. 2023 Oct 29;258(6):108. doi: 10.1007/s00425-023-04262-5.
The review describes tissue-specific and non-cell autonomous molecular responses regulating the root system architecture and function in plants. Phenotypic plasticity of roots relies on specific molecular and tissue specific responses towards local and microscale heterogeneity in edaphic factors. Unlike gravitropism, hydrotropism in Arabidopsis is regulated by MIZU KUSSIE1 (MIZ1)-dependent asymmetric distribution of cytokinin and activation of Arabidopsis response regulators, ARR16 and ARR17 on the lower water potential side of the root leading to higher cell division and root bending. The cortex specific role of Abscisic acid (ABA)-activated SNF1-related protein kinase 2.2 (SnRK2.2) and MIZ1 in elongation zone is emerging for hydrotropic curvature. Halotropism involves clathrin-mediated internalization of PIN FORMED 2 (PIN2) proteins at the side facing higher salt concentration in the root tip, and ABA-activated SnRK2.6 mediated phosphorylation of cortical microtubule-associated protein Spiral2-like (SP2L) in the root transition zone, which results in anisotropic cell expansion and root bending away from higher salt. In hydropatterning, Indole-3-acetic acid 3 (IAA3) interacts with SUMOylated-ARF7 (Auxin response factor 7) and prevents expression of Lateral organ boundaries-domain 16 (LBD16) in air-side of the root, while on wet side of the root, IAA3 cannot repress the non-SUMOylated-ARF7 thereby leading to LBD16 expression and lateral root development. In root vasculature, ABA induces expression of microRNA165/microRNA166 in endodermis, which moves into the stele to target class III Homeodomain leucine zipper protein (HD-ZIP III) mRNA in non-cell autonomous manner. The bidirectional gradient of microRNA165/6 and HD-ZIP III mRNA regulates xylem patterning under stress. Understanding the tissue specific molecular mechanisms regulating the root responses under heterogeneous and stress environments will help in designing climate-resilient crops.
该综述描述了组织特异性和非细胞自主性分子反应，这些反应调节植物的根系结构和功能。根系的表型可塑性依赖于特定的分子和组织特异性反应，以应对土壤因子的局部和微观异质性。与向重力性不同，拟南芥的向水性是由 MIZU KUSSIE1（MIZ1）依赖的细胞分裂素的不对称分布和对根下部水势侧的拟南芥反应调节因子 ARR16 和 ARR17 的激活调节的，导致更高的细胞分裂和根弯曲。皮层特异性的脱落酸（ABA）激活的 SNF1 相关蛋白激酶 2.2（SnRK2.2）和 MIZ1 在伸长区对向水性弯曲的作用正在显现。盐胁迫涉及质膜内陷内化 PIN 形成蛋白 2（PIN2）蛋白，在根尖面对较高盐浓度的一侧，以及 ABA 激活的 SnRK2.6 介导的皮层微管相关蛋白螺旋 2 样（SP2L）的磷酸化，在根过渡区导致各向异性细胞扩展和根弯曲远离较高盐。在水图案形成中，吲哚-3-乙酸 3（IAA3）与 SUMOylated-ARF7（生长素响应因子 7）相互作用，防止 Lateral organ boundaries-domain 16（LBD16）在根的空气侧表达，而在根的湿侧，IAA3 不能抑制非 SUMOylated-ARF7，从而导致 LBD16 表达和侧根发育。在根脉管系统中，ABA 诱导内皮层中 microRNA165/microRNA166 的表达，这些 microRNA165/microRNA166 以非细胞自主性的方式进入中柱，靶向类 III 同源结构域亮氨酸拉链蛋白（HD-ZIP III）mRNA。microRNA165/6 和 HD-ZIP III mRNA 的双向梯度调节胁迫下的木质部模式。了解调节异质和胁迫环境下根系反应的组织特异性分子机制，将有助于设计适应气候变化的作物。
