Donofrio N M, Oh Y, Lundy R, Pan H, Brown D E, Jeong J S, Coughlan S, Mitchell T K, Dean R A
North Carolina State University, Center for Integrated Fungal Research, Raleigh, USA.
Fungal Genet Biol. 2006 Sep;43(9):605-17. doi: 10.1016/j.fgb.2006.03.005. Epub 2006 May 30.
Efficient regulation of nitrogen metabolism likely plays a role in the ability of fungi to exploit ecological niches. To learn about regulation of nitrogen metabolism in the rice blast pathogen Magnaporthe grisea, we undertook a genome-wide analysis of gene expression under nitrogen-limiting conditions. Five hundred and twenty genes showed increased transcript levels at 12 and 48 h after shifting the fungus to media lacking nitrate as a nitrogen source. Thirty-nine of these genes have putative functions in amino acid metabolism and uptake, and include the global nitrogen regulator in M. grisea, NUT1. Evaluation of seven nitrogen starvation-induced genes revealed that all were expressed during rice infection. Targeted gene replacement on one such gene, the vacuolar serine protease, SPM1, resulted in decreased sporulation and appressorial development as well as a greatly attenuated ability to cause disease. Data are discussed in the context of nitrogen metabolism under starvation conditions, as well as conditions potentially encountered during invasive growth in planta.
氮代谢的有效调节可能在真菌利用生态位的能力中发挥作用。为了了解稻瘟病菌Magnaporthe grisea中氮代谢的调节，我们对氮限制条件下的基因表达进行了全基因组分析。将真菌转移到缺乏硝酸盐作为氮源的培养基后，520个基因在12小时和48小时时转录水平升高。其中39个基因在氨基酸代谢和摄取方面具有推定功能，包括稻瘟病菌中的全局氮调节因子NUT1。对七个氮饥饿诱导基因的评估表明，所有这些基因在水稻感染期间均有表达。对其中一个基因——液泡丝氨酸蛋白酶SPM1进行靶向基因置换，导致孢子形成和附着胞发育减少，以及致病能力大大减弱。我们将在饥饿条件下以及植物体内侵入性生长过程中可能遇到的条件下，对氮代谢的背景下的数据进行讨论。
