Hampton Roads Agricultural Research and Extension Center, Virginia Tech, Virginia Beach, VA, USA.
Plant Industry Division, North Carolina Department of Agriculture and Consumer Services, Dobson, NC, USA.
BMC Microbiol. 2023 Aug 12;23(1):219. doi: 10.1186/s12866-023-02956-0.
Anti-desiccant is a class of agrochemicals widely used to protect plants from water stresses, rapid temperature variations, heat and sunburn, frost and freeze damages, transplant shock, and pathogen and pest attack. Although anti-desiccants are generally considered non-toxic to organisms, it is unclear whether they may impact the phyllosphere microbial communities. In this study, three film-forming anti-desiccant products, TransFilm, Vapor Gard, and Wilt-Pruf were applied to the canopy of two boxwood cultivars 'Vardar Valley' and 'Justin Brouwers' on April 13 and August 26, 2021. Shoot samples were collected from boxwood plants treated with each of the three products, as well as nontreated control on June 16, August 26 (before the second treatment), and October 18. Microbial and plant genomic DNA was isolated together and 16S rRNA gene and the extended internal transcribed spacer regions were amplified with PCR and sequenced on a Nanopore MinION platform for bacterial and fungal identification.
Bacterial communities were more diverse than fungal communities. At the phylum level, the boxwood phyllosphere was dominated by Proteobacteria and Ascomycota; at the genus level, Methylobacterium and Shiraia were the most abundant bacteria and fungi, respectively. Among the three film-forming anti-desiccants, Vapor Gard and Wilt-Pruf had more impact than TransFilm on the microbial communities. Specifically, broader impacts were observed on fungal than bacterial community composition and structure, with most affected fungi being suppressed while bacteria promoted.
This study addressed several major knowledge gaps regarding boxwood phyllosphere microbiota and the impact of anti-desiccants on plant microbiome. We identified diverse microbial communities of boxwood, a major evergreen woody crop and an iconic landscape plant. We also found differential effects of three film-forming anti-desiccants on the composition and structure of bacterial and fungal communities. These findings advanced our understanding of the associated microbiome of this landmark plant, enabling growers to fully utilize the potentials of microbiome and three anti-desiccants in improving boxwood health and productivity.
抗蒸腾剂是一类农用化学品，广泛用于保护植物免受水分胁迫、快速温度变化、热和晒伤、霜害和冻害、移栽休克以及病原体和害虫的侵害。虽然抗蒸腾剂通常被认为对生物无毒，但尚不清楚它们是否会影响叶际微生物群落。在这项研究中，三种成膜型抗蒸腾剂产品 TransFilm、Vapor Gard 和 Wilt-Pruf 于 2021 年 4 月 13 日和 8 月 26 日施用于两种黄杨品种“瓦尔达尔谷”和“Justin Brouwers”的树冠上。从用三种产品处理的黄杨植株以及未处理的对照植株上采集枝条样本，分别于 6 月 16 日、8 月 26 日（第二次处理前）和 10 月 18 日采集。将微生物和植物基因组 DNA 一起分离，并用 PCR 扩增 16S rRNA 基因和扩展的内部转录间隔区，并在 Nanopore MinION 平台上进行测序，以鉴定细菌和真菌。
细菌群落比真菌群落更为多样。在门水平上，黄杨叶际以变形菌门和子囊菌门为主；在属水平上，甲基杆菌和石蒜科真菌分别是最丰富的细菌和真菌。在三种成膜型抗蒸腾剂中，Vapor Gard 和 Wilt-Pruf 对微生物群落的影响大于 TransFilm。具体来说，真菌群落组成和结构受到的影响比细菌更大，受影响最大的真菌受到抑制，而细菌则得到促进。
本研究解决了关于黄杨叶际微生物群和抗蒸腾剂对植物微生物组影响的几个主要知识空白。我们鉴定了黄杨这一主要常绿木本作物和标志性景观植物的多样化微生物群落。我们还发现三种成膜型抗蒸腾剂对细菌和真菌群落的组成和结构有不同的影响。这些发现增进了我们对这一标志性植物相关微生物组的理解，使种植者能够充分利用微生物组和三种抗蒸腾剂在提高黄杨健康和生产力方面的潜力。
