White DWR, Woodfield DR, Caradus JR
Plant Physiol. 1998 Mar;116(3):913-21. doi: 10.1104/pp.116.3.913.
A monogenic dominant mutant of white clover (Trifolium repens L.), designated Mortal, which is defective in the formation of adventitious nodal roots, is described. Mortal plants grown at temperatures ranging from 10 to 25 degreesC do not initiate nodal root primordium development. However, all other aspects of plant development are normal, including the formation of lateral roots and wound-induced adventitious roots. In some genetic backgrounds, the Mortal mutation has a temperature-sensitive conditional phenotype. Mortal plants shifted from growing conditions of 20 to 30 degreesC for 2 to 3 d form nodal root meristems. However, new nodes that develop after plants are returned to 20 degreesC exhibit the mutant phenotype. The capacity to form nodal roots on cuttings placed in water is also influenced by the genetic background of the Mortal mutation. Genetic analysis established that the physiological reversion of Mortal to nodal root formation is controlled by at least two separate dominant genetic loci, one for Nodal water response (Now) and one for Nodal temperature response (Not); the Now locus has a dominant epistatic interaction with the Not locus. The conditional nature of Mortal should provide opportunities for the identification of genetic and physiological mechanisms that influence the development of nodal roots.
本文描述了一种白三叶草（Trifolium repens L.）的单基因显性突变体，命名为Mortal，该突变体在不定节根形成方面存在缺陷。在10至25摄氏度温度范围内生长的Mortal植株不会启动节根原基发育。然而，植物发育的所有其他方面都是正常的，包括侧根形成和伤口诱导的不定根形成。在某些遗传背景下，Mortal突变具有温度敏感的条件表型。从20至30摄氏度生长条件转移2至3天的Mortal植株会形成节根分生组织。然而，植株回到20摄氏度后发育的新节点表现出突变表型。置于水中的插条形成节根的能力也受Mortal突变遗传背景的影响。遗传分析表明，Mortal向节根形成的生理回复受至少两个独立的显性遗传位点控制，一个用于节根水响应（Now），一个用于节根温度响应（Not）；Now位点与Not位点存在显性上位相互作用。Mortal的条件性质应为鉴定影响节根发育的遗传和生理机制提供机会。
