Department of Molecular Biology and Ecology of Plants, Tel-Aviv University, Tel-Aviv 69978, Israel.
Fungal Genet Biol. 2011 Jun;48(6):621-30. doi: 10.1016/j.fgb.2011.01.007. Epub 2011 Jan 26.
Apoptotic-like programmed cell death (PCD) occurs naturally in fungi during development and might also be induced by external conditions. Candidate apoptotic genes have been characterized in several model fungal species but not in plant pathogenic fungi. Here we report on the isolation and characterization of BcNMA, an orthologue of the human pro-apoptotic gene HtrA2 from the plant pathogen Botrytis cinerea. The predicted BcNma protein shows high homology to the previously characterized Nma111p from Saccharomyces cerevisiae and despite some structural differences it complemented the function of Nma111p in Δnma111 mutant strains. BcNMA-over-expression and mutant strains had enhanced or reduced appearance of apoptotic markers, respectively. However there was no difference in growth response of the wild type and BcNMA-transgenic strains to application of various stresses, and the effect on pathogenicity was marginal in both the over-expression and mutant strains. When considered together these results suggest that although BcNma has a pro-apoptotic activity, it is not a major regulator of apoptosis. The protein probably has additional roles that are unrelated to apoptosis, which lead to the pleotrophic phenotype of the transgenic strains and lack of a clear effect on stress adaptation and pathogenicity.
细胞程序性死亡（PCD）在真菌的发育过程中自然发生，也可能由外部条件诱导。候选凋亡基因已在几种模式真菌物种中得到了描述，但在植物病原真菌中尚未得到描述。在这里，我们报告了从植物病原菌 Botrytis cinerea 中分离和鉴定的 BcNMA，它是人类促凋亡基因 HtrA2 的同源物。预测的 BcNma 蛋白与人源 HtrA2 高度同源，尽管存在一些结构差异，但它能够补充 Saccharomyces cerevisiae 中已鉴定的 Nma111p 的功能。BcNMA 过表达和突变菌株分别表现出增强或减少的凋亡标记。然而，野生型和 BcNMA 转基因菌株对各种应激应用的生长反应没有差异，并且在过表达和突变菌株中对致病性的影响都很轻微。综合这些结果表明，尽管 BcNma 具有促凋亡活性，但它不是凋亡的主要调节因子。该蛋白可能具有与凋亡无关的其他功能，这导致了转基因菌株的多效表型，以及对应激适应和致病性的影响不明显。
