Plants use a variety of hormonal and peptide signals to control root development, including in adapting root development to cope with nutrient stress. Nitrogen (N) is a major limiting factor in plant growth and in response to N stress plants dramatically modulate root development, including in legumes influencing the formation of N-fixing nodules in response to external N supply. Recently, specific CLE peptides and/or receptors important for their perception, including CLV1 and CLV2, have been found to play important roles in root development in a limited number of species, including in some cases the response to N. In the legume Medicago truncatula, this response also appears to be influenced by RDN1, a member of the hydroxyproline O-arabinosyltransferase (HPAT) family which can modify specific CLE peptides. However, it not known if this signalling pathway plays a central role in root development across species, in particular root responses to N. In this study, we sought to systematically examine the role of homologues of these genes in root development of the legume pea (Pisum sativum. L) and non-legume tomato (Solanum lycopersicum) using a mutant based approach. This included a detailed examination of root development in response to N in these mutant series in tomato. We found no evidence for a role of these genes in pea seedling root development. Furthermore, the CLV1-like FAB gene did not influence tomato root development, including N response. In contrast, both CLV2 and the HPAT FIN appear to positively influence root size in tomato but do not mediate root responses to N. These suggest a relatively species-specific role for these genes in root development, including N regulation of root architecture.

中文翻译：

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CLV1，CLV2和HPAT同源物在根系发育氮调控中的作用

植物利用各种激素和肽信号来控制根的发育，包括适应根的发育以应对营养胁迫。氮（N）是植物生长的主要限制因素，对N胁迫的反应极大地调节了植物的根系发育，包括影响外部N供应的影响豆类固氮结节形成的豆类。最近，已发现对他们的感知重要的特定CLE肽和/或受体，包括CLV1和CLV2，在少数物种的根系发育中起着重要作用，包括在某些情况下对N的反应。 ，该反应似乎也受到RDN1的影响，RDN1是羟脯氨酸O-阿拉伯糖基转移酶（HPAT）家族的成员，可以修饰特定的CLE肽。然而，尚不清楚该信号传导途径是否在物种间的根系发育中起着中心作用，特别是对氮的根系响应。在这项研究中，我们试图系统地检查这些基因的同源物在豆类豌豆（Pisum sativum）中的作用。 L）和非豆科番茄（Solanum lycopersicum）使用基于突变的方法。这包括对番茄中这些突变系列中响应N的根发育的详细检查。我们没有发现这些基因在豌豆幼苗根系发育中起作用的证据。此外，CLV1样FAB基因不影响番茄的根系发育，包括N响应。相反，CLV2和HPAT FIN似乎都积极影响番茄的根大小，但不介导对N的根响应。