Lasok Hanna, Nziengui Hugues, Kochersperger Philip, Ditengou Franck Anicet
Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Kraków, Poland.
Faculty of Biology, Institute of Biology II, Albert Ludwigs University Freiburg, 79104 Freiburg, Germany.
Plants (Basel). 2023 Dec 5;12(24):4076. doi: 10.3390/plants12244076.
The continuous growth of roots depends on their ability to maintain a balanced ratio between cell production and cell differentiation at the tip. This process is regulated by the hormonal balance of cytokinin and auxin. However, other important regulators, such as plant folates, also play a regulatory role. In this study, we investigated the impact of the folate precursor para-aminobenzoic acid (PABA) on root development. Using pharmacological, genetic, and imaging approaches, we show that the growth of roots is repressed by either supplementing the growth medium with PABA or overexpressing the PABA synthesis gene . This is associated with a smaller root meristem consisting of fewer cells. Conversely, reducing the levels of free root endogenous PABA results in longer roots with extended meristems. We provide evidence that PABA represses Arabidopsis root growth in a folate-independent manner and likely acts through two mechanisms: (i) the G2/M transition of cell division in the root apical meristem and (ii) promoting premature cell differentiation in the transition zone. These data collectively suggest that PABA plays a role in Arabidopsis root growth at the intersection between cell division and cell differentiation.
根的持续生长取决于其在根尖维持细胞产生与细胞分化之间平衡比例的能力。这一过程受细胞分裂素和生长素的激素平衡调节。然而，其他重要的调节因子，如植物叶酸，也发挥着调节作用。在本研究中，我们研究了叶酸前体对氨基苯甲酸（PABA）对根发育的影响。使用药理学、遗传学和成像方法，我们发现，通过在生长培养基中添加PABA或过表达PABA合成基因，根的生长均受到抑制。这与由较少细胞组成的较小根分生组织有关。相反，降低根内源性游离PABA的水平会导致根更长且分生组织延长。我们提供的证据表明，PABA以不依赖叶酸的方式抑制拟南芥根的生长，可能通过两种机制起作用：（i）根尖分生组织中细胞分裂的G2/M期转换；（ii）促进过渡区细胞过早分化。这些数据共同表明，PABA在拟南芥根生长中，在细胞分裂和细胞分化的交叉点上发挥作用。
