Isolation and characterization of rtcs, a maize mutant deficient in the formation of nodal roots
Isolation and characterization of rtcs, a maize mutant deficient in the formation of nodal roots
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DOI：
10.1046/j.1365-313x.1996.10050845.x
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发表时间：
1996-11-01
期刊：
影响因子：
7.2
通讯作者：
Feix, G
中科院分区：
文献类型：
--
作者：
Hetz, W;Hochholdinger, F;Feix, G
玉米的根系由主根和数量不等的侧根、种子根、冠根和支撑根组成。除了主根和一些在中胚轴形成的小根外，所有其他根都生长在节区，即胚性盾片节和地下茎节以及地上茎节。除了它们在水分和养分吸收中的作用之外，这些根中的一些（冠根和支撑根）对于植物的抗倒伏性是必不可少的。冠根的这一特性现已成功地用于筛选燧石自交系与En转座子系杂交的分离F-2群体。两个等位基因根缺陷突变体已被分离，并已被指定为rtcs-1和rtcs-2，因为他们完全缺乏冠状和侧根的形成。它们依靠初生根的能力来支持正在发育的植物的生长。单基因和隐性突变体似乎在早期根形成功能的影响，因为没有原基形成的情况下，胚生侧种子或茎衍生冠根。Rtcs位点可以定位到1号染色体的短臂与共分离的RAPD标记的帮助。该突变的影响似乎是高度特异性的，因为没有观察到对植物其他部分的多效性影响。然而，在突变体的中胚轴区域仍然可以诱导不定根的形成。
The root system of maize consists of the primary root and a variable number of lateral seminal-, crown- and brace roots. Except for the primary root and some minor roots forming at the mesocotyl, all other roots grow out of nodal regions, namely, the embryogenic scutellar node and the underground-as well as the lower aboveground stem nodes. Besides their role in water and nutrient uptake, some of these roots (crown- and brace roots) are essential for the lodging resistance of the plants. This property of the crown roots has now been successfully used for screening a segregating F-2 population of a cross between a flint inbred line and an En transposon line. Two allelic root-deficient mutants have been isolated and have been designated rtcs-1 and rtcs-2 for their complete lack of formation of crown- and lateral seminal roots. They survive by the ability of the primary root to support the growth of the developing plant. The monogenic and recessive mutants appear to be affected in an early root-forming function since no primordia are formed either in the case of embryo-borne lateral seminal or stem-derived crown roots. The Rtcs locus could be mapped to the short arm of chromosome 1 with the help of a co-segregating RAPD marker. The effect of the mutation seems to be highly specific since no pleiotropic effects on other parts of the plants have been observed. The formation of adventitious roots can, however, still be induced in the mesocotyl region of the mutant.