Yang Z, Park H, Lacy G H, Cramer C L
Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg 24061-0330.
Plant Cell. 1991 Apr;3(4):397-405. doi: 10.1105/tpc.3.4.397.
Potato genes encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) were expressed in response to pathogen, elicitor, and wounding. HMGR catalyzes the rate-limiting step in isoprenoid biosynthesis leading to accumulation of phytoalexins and steroid glycoalkaloids. Wounding caused increases in HMGR mRNA levels. A rapid and transient peak occurred 30 minutes after wounding, followed by a slower peak at 14 hours; both were correlated with increased enzyme activity. Induction of HMGR mRNA by the soft rot pathogen Erwinia carotovora subsp carotovora or arachidonic acid began 8 hours after challenge and continued through 22 hours. Potato HMGR is encoded by a gene family. An HMGR gene-specific probe was used to demonstrate that one isogene of the HMGR family is pathogen activated and is distinct from isogene(s) that are wound activated. This provides evidence that defense-related increases in HMGR activity are due to mRNA level increases and that HMGR isogenes are activated differentially by wounding or pathogen challenge.
编码3-羟基-3-甲基戊二酰辅酶A还原酶（HMGR）的马铃薯基因在病原体、激发子和创伤刺激下表达。HMGR催化类异戊二烯生物合成中的限速步骤，导致植保素和甾体糖生物碱的积累。创伤导致HMGR mRNA水平升高。创伤后30分钟出现快速且短暂的峰值，随后在14小时出现较慢的峰值；两者均与酶活性增加相关。软腐病原菌胡萝卜软腐欧文氏菌胡萝卜亚种或花生四烯酸对HMGR mRNA的诱导在侵染后8小时开始，并持续至22小时。马铃薯HMGR由一个基因家族编码。使用HMGR基因特异性探针证明，HMGR家族的一个同基因被病原体激活，且与被创伤激活的同基因不同。这提供了证据，表明与防御相关的HMGR活性增加是由于mRNA水平升高，并且HMGR同基因在创伤或病原体侵染时被差异激活。
