2022-12-14 ペンシルベニア州立大学(PennState)
この研究では、農業科学大学の研究者たちが、Metarhizium robertsiiという菌がトウモロコシに及ぼす影響について研究した。その結果、この菌がトウモロコシに定着すると、植物は別の菌である C. heterostrophus の影響を受けにくくなることがわかりました。C. heterostrophus は南部トウモロコシ葉枯病という病気を引き起こす菌です。
彼らはまた、M. robertsiiで処理した種子から育てたトウモロコシの苗は、未処理の種子から育てた苗よりも背が高く、重くなることも発見しました。
昆虫学の教授であるMary Barbercheckは、最近PLOS Oneに発表されたこの発見は、M. robertsiiが作物を育て、特に有機栽培者にとって、病気を防ぐのに重要なツールになる可能性を示唆する、と述べました。
<関連情報>
- https://www.psu.edu/news/agricultural-sciences/story/corn-colonizing-fungus-may-help-crop-repel-disease-grow-larger/
- https://journals.plos.org/plosone/article/comments?id=10.1371/journal.pone.0272944
植物細菌による植物病原体の抑制とトウモロコシの防御能の調節。 Endophytic Metarhizium robertsii suppresses the phytopathogen, Cochliobolus heterostrophus and modulates maize defenses
Imtiaz Ahmad ,María del Mar Jiménez-Gasco,Dawn S. Luthe,Mary E. Barbercheck
PLOS One Published: September 22, 2022
DOI:https://doi.org/10.1371/journal.pone.0272944
Abstract
Fungi in the genus Metarhizium (Hypocreales: Clavicipitaceae) are insect-pathogens and endophytes that can benefit their host plant through growth promotion and protection against stresses. Cochliobolus heterostrophus (Drechsler) Drechsler (Pleosporales: Pleosporaceae) is an economically-significant phytopathogenic fungus that causes Southern Corn Leaf Blight (SCLB) in maize. We conducted greenhouse and lab-based experiments to determine the effects of endophytic M. robertsii J.F. Bisch., Rehner & Humber on growth and defense in maize (Zea mays L.) infected with C. heterostrophus. We inoculated maize seeds with spores of M. robertsii and, at the 3 to 4-leaf stage, the youngest true leaf of M. robertsii-treated and untreated control plants with spores of C. heterostrophus. After 96 h, we measured maize height, above-ground biomass, endophytic colonization by M. robertsii, severity of SCLB, and expression of plant defense genes and phytohormone content. We recovered M. robertsii from 74% of plants grown from treated seed. The severity of SCLB in M. robertsii-treated maize plants was lower than in plants inoculated only with C. heterostrophus. M. robertsii-treated maize inoculated or not inoculated with C. heterostrophus showed greater height and above-ground biomass compared with untreated control plants. Height and above-ground biomass of maize co-inoculated with M. robertsii and C. heterostrophus were not different from M. robertsii-treated maize. M. robertsii modulated the expression of defense genes and the phytohormone content in maize inoculated with C. heterostrophus compared with plants not inoculated with C. heterostrophus and control plants. These results suggest that endophytic M. robertsii can promote maize growth and reduce development of SCLB, possibly by induced systemic resistance mediated by modulation of phytohormones and expression of defense and growth-related genes in maize.
