Galloway R E, Mets L J
Department of Biology, Washington University, St. Louis, Missouri 63130.
Plant Physiol. 1984 Mar;74(3):469-74. doi: 10.1104/pp.74.3.469.
A series of Chlamydomonas reinhardii mutants were selected for resistance to the herbicides atrazine, bromacil, and diuron. Four of these have reduced herbicide binding to the thylakoid membranes and show the non-Mendelian inheritance pattern characteristic of chloroplast genes. These mutants show a variety of selective alterations in binding of the three herbicides. These changes account for the observed patterns of in vivo cross-resistance. Analyses of chloroplast gene recombination indicate that these four mutations are in the same gene. Overall, the results suggest that this gene codes for a protein component of the herbicide binding site. One of the mutants has slow phototrophic growth and altered electron transport as has been observed in atrazine-resistant higher plant varieties, but the others are normal in these respects. The slow growth characteristic of this mutant seems to be the consequence of the same mutation which confers herbicide resistance.The mutants isolated also include a large number which achieve resistance by some secondary mechanism. These are all nuclear gene mutations, and represent numerous loci. They also show a variety of patterns of cross-resistance, but the mechanisms behind them have not yet been investigated.
筛选出了一系列莱茵衣藻突变体，使其对除草剂阿特拉津、除草定和敌草隆具有抗性。其中四个突变体与除草剂结合到类囊体膜上的能力降低，并且表现出叶绿体基因特有的非孟德尔遗传模式。这些突变体在三种除草剂结合方面表现出多种选择性改变。这些变化解释了观察到的体内交叉抗性模式。叶绿体基因重组分析表明，这四个突变位于同一个基因中。总体而言，结果表明该基因编码除草剂结合位点的一种蛋白质成分。其中一个突变体具有缓慢的光合生长和改变的电子传递，这在抗阿特拉津的高等植物品种中也有观察到，但其他突变体在这些方面是正常的。这个突变体的缓慢生长特性似乎是赋予除草剂抗性的同一突变的结果。分离出的突变体中还包括大量通过某种二级机制获得抗性的突变体。这些都是核基因突变，代表了许多基因座。它们也表现出多种交叉抗性模式，但背后的机制尚未研究。
