Kloepper J W, Gutiérrez-Estrada A, McInroy J A
Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA.
Can J Microbiol. 2007 Feb;53(2):159-67. doi: 10.1139/w06-114.
For several years, we have noticed that plant growth-promoting rhizobacteria (PGPR), which consistently promote plant growth in greenhouse tests during spring, summer, and fall, fail to elicit plant growth promotion during the midwinter under ambient light conditions. This report tests the hypothesis that photoperiod regulates elicitation of growth promotion and induced systemic resistance (ISR) by PGPR. A commercially available formulation of PGPR strains Bacillus subtilis GB03 and Bacillus amyloliquefaciens IN937a (BioYield) was used to grow tomato and pepper transplants under short-day (8 h of light) (SD) and long-day (12 h of light) (LD) conditions. Results of many experiments indicated that under LD conditions, BioYield consistently elicited significant increases in root and shoot mass as well as in several parameters of root architecture. However, under SD conditions, such increases were not elicited. Differential root colonization of plants grown under LD and SD conditions and changes in leachate quality partially account for these results. BioYield elicited ISR in tomato and pepper under both LD and SD conditions, indicating that although growth promotion was not elicited under SD conditions, induced resistance was. Overall, the results indicate that PGPR-mediated growth promotion is regulated by photoperiod, while ISR is not.
几年来，我们注意到，在春、夏、秋三季的温室试验中始终能促进植物生长的促生根际细菌（PGPR），在冬季中期的自然光照条件下却无法促进植物生长。本报告检验了光周期调节PGPR诱导植物生长促进和诱导系统抗性（ISR）这一假设。使用市售的PGPR菌株枯草芽孢杆菌GB03和解淀粉芽孢杆菌IN937a（BioYield）制剂，在短日照（8小时光照）（SD）和长日照（12小时光照）（LD）条件下培育番茄和辣椒移植苗。许多实验结果表明，在长日照条件下，BioYield始终能显著增加根和地上部的质量以及根系结构的几个参数。然而，在短日照条件下，并未出现这种增加。长日照和短日照条件下生长的植物根系定殖差异以及渗滤液质量的变化部分解释了这些结果。BioYield在长日照和短日照条件下均能诱导番茄和辣椒产生ISR，这表明尽管在短日照条件下未诱导出植物生长促进，但诱导抗性是存在的。总体而言，结果表明PGPR介导的植物生长促进受光周期调节，而ISR则不受光周期调节。
