Hochholdinger F, Park W J, Feix G H
Institut für Biologie III, Albert-Ludwigs-Universität-Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany.
Plant Physiol. 2001 Mar;125(3):1529-39. doi: 10.1104/pp.125.3.1529.
Lateral roots play an important role in water and nutrient uptake largely by increasing the root surface area. In an effort to characterize lateral root development in maize (Zea mays), we have isolated from Mutator (Mu) transposon stocks and characterized two nonallelic monogenic recessive mutants: slr1 and slr2 (short lateral roots1 and 2), which display short lateral roots as a result of impaired root cell elongation. The defects in both mutants act specifically during early postembryonic root development, affecting only the lateral roots emerging from the embryonic primary and seminal roots but not from the postembryonic nodal roots. These mutations have no major influence on the aboveground performance of the affected plants. The double mutant slr1; slr2 displays a strikingly different phenotype than the single mutants. The defect in slr1; slr2 does not only influence lateral root specific cell elongation, but also leads to disarranged cellular patterns in the primary and seminal roots. However, the phase-specific nature of the single mutants is retained in the double mutant, indicating that the two loci cooperate in the wild type to maintain the lateral root specificity during a short time of early root development.
侧根在水分和养分吸收中发挥着重要作用，主要是通过增加根表面积来实现。为了表征玉米（Zea mays）侧根的发育情况，我们从Mutator（Mu）转座子库中分离并鉴定了两个非等位单基因隐性突变体：slr1和slr2（短侧根1和2），它们由于根细胞伸长受损而表现出短侧根。两个突变体的缺陷都在胚胎后根发育早期特异性地起作用，仅影响从胚胎主根和种子根长出的侧根，而不影响胚胎后节根长出的侧根。这些突变对受影响植株的地上部分表现没有重大影响。双突变体slr1; slr2表现出与单突变体截然不同的表型。slr1; slr2的缺陷不仅影响侧根特定细胞的伸长，还导致主根和种子根中细胞模式紊乱。然而，单突变体的阶段特异性在双突变体中得以保留，这表明在野生型中，这两个基因座在早期根发育的短时间内协同作用以维持侧根特异性。
