Severity of mutant phenotype in a series of chlorophyll-deficient wheat mutants depends on light intensity and the severity of the block in chlorophyll synthesis
Severity of mutant phenotype in a series of chlorophyll-deficient wheat mutants depends on light intensity and the severity of the block in chlorophyll synthesis
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DOI：
10.1104/pp.112.2.821
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发表时间：
1996-10-01
期刊：
影响因子：
7.4
通讯作者：
Staehelin, LA
中科院分区：
文献类型：
--
作者：
Falbel, TG;Meehl, JB;Staehelin, LA
小麦一系列等位叶绿素突变体的分析，其在叶绿素（Chl）合成中具有部分阻断，因此Chl供应有限，这加强了Chl结合蛋白的稳定积累需要Chl的原理，并且只有当Chl供应严重受限时才积累反应中心。根据叶绿素积累的速率（由突变的严重程度决定）和叶绿素及其前体的周转率（由植物生长的环境决定），突变体各自达到叶绿素合成和降解的平衡。这些突变体共同产生了一系列表型。在最苛刻的条件下（高光照），植物中的叶绿素合成的温和块有非常少的叶绿素和叶绿素蛋白和膜堆栈类似的致死性黄嘌呤突变体的大麦生长在低至中等光强度（有更严重的块）的类囊体的膜。相反，当在弱光条件下生长时，具有中等块的相同植物具有类似于野生型的类囊体。Chl b缺陷突变体的表型范围广泛，历史上产生了更多的混乱，而不是启示，但无与伦比的生长条件现在可以解释文献中报道的差异。
Analyses of a series of allelic chlorina mutants of wheat (Triticum aestivum L.), which have partial blocks in chlorophyll (Chl) synthesis and, therefore, a limited Chl supply, reinforce the principle that Chl is required for the stable accumulation of Chl-binding proteins and that only reaction centers accumulate when the supply of Chl is severely limited. Depending on the rate of Chl accumulation (determined by the severity of the mutation) and on the rate of turnover of Chl and its precursors (determined by the environment in which the plant is grown), the mutants each reach an equilibrium of Chl synthesis and degradation. Together these mutants generate a spectrum of phenotypes. Under the harshest conditions (high illumination), plants with moderate blocks in Chl synthesis have membranes with very little Chl and Chl-proteins and membrane stacks resembling the thylakoids of the lethal xantha mutants of barley grown at low to medium light intensities (which have more severe blocks). In contrast, when grown under low-light conditions the same plants with moderate blocks have thylakoids resembling those of the wild type. The wide range of phenotypes of Chl b-deficient mutants has historically produced more confusion than enlightenment, but incomparable growth conditions can now explain the discrepancies reported in the literature.