INRAE, Université Côte d'Azur, CNRS, ISA, F-06903 Sophia Antipolis, France.
Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, Toulouse INP, 31320 Auzeville-Tolosane, France.
J Exp Bot. 2023 Sep 29;74(18):5752-5766. doi: 10.1093/jxb/erad208.
Root-knot nematodes (RKN) from the genus Meloidogyne induce the dedifferentiation of root vascular cells into giant multinucleate feeding cells. These feeding cells result from an extensive reprogramming of gene expression, and auxin is known to be a key player in their development. However, little is known about how the auxin signal is transmitted during giant cell development. Integrative analyses combining transcriptome and small non-coding RNA datasets with the specific sequencing of cleaved transcripts identified genes targeted by miRNAs in tomato (Solanum lycopersicum) galls. The two auxin-responsive transcription factors ARF8A and ARF8B, and their miRNA167 regulators, were identified as robust gene-miRNA pair candidates to be involved in the tomato response to M. incognita. Spatiotemporal expression analysis using promoter-β-glucuronidase (GUS) fusions showed the up-regulation of ARF8A and ARF8B in RKN-induced feeding cells and surrounding cells. The generation and phenotyping of CRISPR (clustered regularly interspaced palindromic repeats) mutants demonstrated the role of ARF8A and ARF8B in giant cell development and allowed the characterization of their downstream regulated genes.
根结线虫属的根结线虫会诱导根系血管细胞去分化为巨型多核取食细胞。这些取食细胞是基因表达广泛重编程的结果，生长素被认为是其发育的关键因素。然而，生长素信号在巨型细胞发育过程中的传递方式知之甚少。将转录组和小非编码 RNA 数据集与切割转录本的特异性测序相结合的综合分析，鉴定了番茄（Solanum lycopersicum）根瘤中 miRNA 靶向的基因。两个生长素反应转录因子 ARF8A 和 ARF8B 及其 miRNA167 调节因子被鉴定为与番茄对 M. incognita 反应相关的强有力的基因-miRNA 对候选物。使用启动子-β-葡萄糖醛酸酶（GUS）融合进行的时空表达分析显示，ARF8A 和 ARF8B 在 RKN 诱导的取食细胞和周围细胞中上调。CRISPR（成簇规律间隔短回文重复）突变体的生成和表型分析证明了 ARF8A 和 ARF8B 在巨型细胞发育中的作用，并允许对其下游调控基因进行表征。
