光下叶绿素缺乏的大麦突变体NYB中叶绿素合成再探

研究一种原叶绿素酯还原酶（POR）的大麦突变体Ⅳ阳光下合成叶绿素的结果表明，NYB中PORB的含量比野生型低。NYB前质体中原片层体的大小和数量与野生型差不多，但其结构比野生型的松散。暗中生长的突变体内POR蛋白复合物LHPP比野生型少。不同光照强度下叶绿素积累的结果显示，光照度越强，突变体与野生型的叶绿素差异越显著。由于porB是单拷贝的，所以推测突变体中部分porB mRNA可能产生错误的剪切拼接，以致光下突变体Ⅳ阳仍然能合成叶绿素。

Further Study on Chlorophyll Synthesis of a Chlorophyll-Less Barley Mutant NYB in Light

The chlorophyll synthesis of a protochlorophyllide oxidoreductase （POR） in barley mutant NYB was studied, and we found that the content of PORB was less in NYB than that in the wild type （WT）. In the etioplasts of NYB, prolamellar bodies had similar size and amount with WT, but had a more incompact structure. The content of POR complex LHPP also was much less in the dark-grown mutant than that in WT. The data about the accumulation of chlorophyll in different intensities of light demonstrated that the stronger the illumination was, the mole prominent difference of chlorophylls between the mutant and WT was. As the porB gene is a single copy, we extrapolated that probably partial porB mRNAs had wrong cutting and splicing, and therefore the mutant NYB could synthesize chloroohyll in the light.