PDF(Pubmed)
Abstract：
Climate-induced drought impacts plant growth and development. Recurring droughts increase the demand for water for food production and landscaping. Native plants in the Intermountain West region of the US are of keen interest in low water use landscaping as they are acclimatized to dry and cold environments. These native plants do very well at their native locations but are difficult to propagate in landscape. One of the possible reasons is the lack of associated microbiome in the landscaping. Microbiome in the soil contributes to soil health and impacts plant growth and development. Here, we used the bulk soil from the native plant Ceanothus velutinus (snowbrush ceanothus) as inoculant to enhance its propagation. Snowbrush ceanothus is an ornamental plant for low-water landscaping that is hard to propagate asexually. Using 50% native bulk soil as inoculant in the potting mix significantly improved the survival rate of the cuttings compared to no-treated cuttings. Twenty-four plant growth-promoting rhizobacteria (PGPR) producing indole acetic acid (IAA) were isolated from the rhizosphere and roots of the survived snowbrush. Seventeen isolates had more than 10µg/mL of IAA were shortlisted and tested for seven different plant growth-promoting (PGP) traits; 76% showed nitrogen-fixing ability on Norris Glucose Nitrogen free media,70% showed phosphate solubilization activity, 76% showed siderophore production, 36% showed protease activity, 94% showed ACC deaminase activity on DF-ACC media, 76% produced catalase and all of isolates produced ammonia. Eight of seventeen isolates, CK-6, CK-22, CK-41, CK-44, CK-47, CK-50, CK-53, and CK-55, showed an increase in shoot biomass in Arabidopsis thaliana. Seven out of eight isolates were identified as Pseudomonas, except CK-55, identified as Sphingobium based on 16S rRNA gene sequencing. The shortlisted isolates are being tested on different grain and vegetable crops to mitigate drought stress and promote plant growth.
摘要：
气候引起的干旱影响植物的生长发育。经常性的干旱增加了对粮食生产和景观美化用水的需求。美国西部山区的本地植物对低用水景观非常感兴趣，因为它们适应了干燥和寒冷的环境。这些本地植物在其本地位置表现非常好，但难以在景观中传播。可能的原因之一是园林绿化中缺乏相关的微生物组。土壤中的微生物组有助于土壤健康并影响植物的生长和发育。这里,我们使用本地植物Ceanothusvelutinus（雪刷ceanothus）的散装土壤作为接种剂，以增强其繁殖。雪刷ceanothus是一种用于低水位景观的观赏植物，很难无性繁殖。与未处理的插条相比，在盆栽混合物中使用50％的天然散装土壤作为接种剂可显着提高插条的存活率。从存活的雪刷的根际和根部分离出24种产生吲哚乙酸（IAA）的促进植物生长的根际细菌（PGPR）。17个分离株的IAA含量超过10µg/mL，并进行了7种不同的植物生长促进（PGP）性状的测试；76％的人在Norris葡萄糖无氮培养基上表现出固氮能力，70%显示磷酸盐溶解活性，76%显示铁载体生产，36%显示蛋白酶活性，94%在DF-ACC培养基上显示ACC脱氨酶活性，76％产生过氧化氢酶，所有分离物产生氨。十七个分离物中的八个，CK-6，CK-22，CK-41，CK-44，CK-47，CK-50，CK-53和CK-55显示拟南芥的芽生物量增加。8个分离物中有7个被鉴定为假单胞菌,除CK-55外，根据16SrRNA基因测序鉴定为鞘氨醇。入围的分离株正在不同的谷物和蔬菜作物上进行测试，以减轻干旱胁迫并促进植物生长。
