CAJ | 학술논문

从植物根际土壤中筛选出1株植物根际促生细菌( PGPR)，并对其进行分子生物学鉴定。在盆栽试验条件下，以侧柏为材料，研究接种 PGPR在4个水分梯度(正常浇水、轻度干旱、中度干旱和重度干旱)下对侧柏生理生态特征及生长的影响。通过形态学观察、生理生化测定、16S rDNA基因测序及系统发育树分析，筛选出的 PGPR鉴定为蜡样芽孢杆菌。正常浇水的情况下，接种蜡样芽孢杆菌对侧柏抗氧化酶、渗透调节物质和膜脂过氧化产物的影响较小；随着干旱胁迫强度的增加，接种蜡样芽孢杆菌可显著增加抗氧化酶活性，但显著降低渗透调节物质和膜脂过氧化产物的积累。接种蜡样芽孢杆菌均可不同程度地提高侧柏生长素、赤霉素和玉米素的含量。正常浇水和轻度干旱时，接种蜡样芽孢杆菌显著提高脱落酸含量，而重度干旱时 PGPR 处理的脱落酸含量降低23.81%。此外，接种蜡样芽孢杆菌显著增加侧柏干物质积累，且随着干旱胁迫强度的增加，对根系干物质积累的影响越来越小，而对地上部的影响越来越大。综合分析认为，干旱生境下接种植物根际促生细菌，侧柏能够通过调节保护酶活性和渗透调节物质含量，促进一些激素类物质的产生来减轻干旱对植物生长造成的伤害，促进干物质积累。
종식물근제토양중사선출1주식물근제촉생세균( PGPR)，병대기진행분자생물학감정。재분재시험조건하，이측백위재료，연구접충 PGPR재4개수분제도(정상요수、경도간한、중도간한화중도간한)하대측백생리생태특정급생장적영향。통과형태학관찰、생리생화측정、16S rDNA기인측서급계통발육수분석，사선출적 PGPR감정위사양아포간균。정상요수적정황하，접충사양아포간균대측백항양화매、삼투조절물질화막지과양화산물적영향교소；수착간한협박강도적증가，접충사양아포간균가현저증가항양화매활성，단현저강저삼투조절물질화막지과양화산물적적루。접충사양아포간균균가불동정도지제고측백생장소、적매소화옥미소적함량。정상요수화경도간한시，접충사양아포간균현저제고탈락산함량，이중도간한시 PGPR 처리적탈락산함량강저23.81%。차외，접충사양아포간균현저증가측백간물질적루，차수착간한협박강도적증가，대근계간물질적루적영향월래월소，이대지상부적영향월래월대。종합분석인위，간한생경하접충식물근제촉생세균，측백능구통과조절보호매활성화삼투조절물질함량，촉진일사격소류물질적산생래감경간한대식물생장조성적상해，촉진간물질적루。
A plant growth-promoting rhizobacterium ( PGPR) was screened from plant rhizospheric soil by the bioassay methods of wheat leaf green retaining and radish cotyledon growth and isolated,and then,the PGPR was identified with molecular biology means. A pot experiment of Platycladus orientalis was conducted with controlled water supply ( control, light drought stress,moderate drought stress and severe drought stress) and the PGPR was inoculated. Effects of the plant growth-promoting rhizobacteria on dry weight,antioxidant enzyme,and endogenous hormone of P. orientalis was studied in the present research. According to the morphologic characteristics,physiological biochemical properties and phylogenetic analysis of 16S rRNA genes,the PGPR isolated in the present study was identified as Bacillus cereus. Under well-watered conditions,there was little effect of PGPR inoculation on antioxidant enzyme,osmotic adjustment substance,and lipid peroxidation products of P. orientalis. Under drought stress conditions,B. cereus inoculation increased the antioxidant enzyme activities. However,osmotic adjustment substance,and lipid peroxidation products were decreased as a result of PGPR inoculation. Regardless of the water status,the contents of indoleacetic acid,gibberellins,and zeatin in P. orientalis were significantly increased as a result of B. cereus inoculation. Besides,PGPR decreased abscisic acid content by 23. 81% under severe drought stress. The dry matter accumulation of P. orientalis was significantly improved due to B. cereus inoculation. Additionally,B. cereus inoculation promoted shoots dry matter accumulation of P. orientalis,however, it had a decreasing effect on roots dry mass accumulation with the increasing drought intensity. The results suggest that B. cereus inoculation could effectively alleviate the damage of drought stress to P. orientalis by regulating the antioxidant enzyme and osmotic adjustment substance,and stimulating some endogenous hormone production. In summary,PGPR inoculation could improve drought resistance of P. orientalis,and improve the shoot dry matter accumulation,and it would be a supplementary measure for afforestation in arid and semi-arid environment.