Muday G K, Lomax T L, Rayle D L
Department of Biology, Wake Forest University, Winston-Salem, NC 27109-7325, USA.
Planta. 1995;195(4):548-53. doi: 10.1007/BF00195714.
Roots of the tomato (Lycopersicon esculentum, Mill.) mutant (diageotropica (dgt) exhibit an altered phenotype. These roots are agravitropic and lack lateral roots. Relative to wild-type (VFN8) roots, dgt roots are less sensitive to growth inhibition by exogenously applied IAA and auxin transport inhibitors (phytotropins), and the roots exhibit a reduction in maximal growth inhibition in response to ethylene. However, IAA transport through roots, binding of the phytotropin, tritiated naphthylphthalamic acid ([3H]NPA), to root microsomal membranes, NPA-sensitive IAA uptake by root segments, and uptake of [3H]NPA into root segments are all similar in mutant and wild-type roots. We speculate that the reduced sensitivity of dgt root growth to auxin-transport inhibitors and ethylene is an indirect result of the reduction in sensitivity to auxin in this single gene, recessive mutant. We conclude that dgt roots, like dgt shoots, exhibit abnormalities indicating they have a defect associated with or affecting a primary site of auxin perception or action.
番茄（Lycopersicon esculentum, Mill.）突变体（斜生（dgt））的根表现出改变的表型。这些根是无向重力性的且缺乏侧根。相对于野生型（VFN8）根，dgt根对外源施加的吲哚 - 3 - 乙酸（IAA）和生长素运输抑制剂（植物生长素）的生长抑制不太敏感，并且根对乙烯的最大生长抑制表现出降低。然而，IAA通过根的运输、植物生长素（氚标记的萘基邻苯二甲酸（[3H]NPA））与根微粒体膜的结合、根段对NPA敏感的IAA摄取以及[3H]NPA进入根段在突变体根和野生型根中都相似。我们推测dgt根生长对生长素运输抑制剂和乙烯敏感性降低是这个单基因隐性突变体对生长素敏感性降低的间接结果。我们得出结论，dgt根与dgt茎一样，表现出异常，表明它们存在与生长素感知或作用的主要位点相关或影响该位点的缺陷。
