IKBM, Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, 4036, Stavanger, Norway.
Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433, Ås, Norway.
BMC Plant Biol. 2021 Apr 16;21(1):183. doi: 10.1186/s12870-021-02960-4.
PROTEIN PHOSPHATASE 2A (PP2A) expression is crucial for the symbiotic association between plants and various microbes, and knowledge on these symbiotic processes is important for sustainable agriculture. Here we tested the hypothesis that PP2A regulatory subunits, especially B'φ and B'θ, are involved in signalling between plants and mycorrhizal fungi or plant-growth promoting bacteria.
Treatment of tomato plants (Solanum lycopersicum) with the plant growth-promoting rhizobacteria (PGPR) Azospirillum brasilense and Pseudomonas simiae indicated a role for the PP2A B'θ subunit in responses to PGPR. Arbuscular mycorrhizal fungi influenced B'θ transcript levels in soil-grown plants with canonical arbuscular mycorrhizae. In plant roots, transcripts of B'φ were scarce under all conditions tested and at a lower level than all other PP2A subunit transcripts. In transformed tomato plants with 10-fold enhanced B'φ expression, mycorrhization frequency was decreased in vermiculite-grown plants. Furthermore, the high B'φ expression was related to abscisic acid and gibberellic acid responses known to be involved in plant growth and mycorrhization. B'φ overexpressor plants showed less vigorous growth, and although fruits were normal size, the number of seeds per fruit was reduced by 60% compared to the original cultivar.
Expression of the B'θ gene in tomato roots is strongly influenced by beneficial microbes. Analysis of B'φ overexpressor tomato plants and established tomato cultivars substantiated a function of B'φ in growth and development in addition to a role in mycorrhization.
蛋白磷酸酶 2A（PP2A）的表达对于植物与各种微生物的共生关系至关重要，了解这些共生过程对于可持续农业至关重要。在这里，我们检验了这样一个假设，即 PP2A 调节亚基，特别是 B'φ 和 B'θ，参与了植物与菌根真菌或植物促生细菌之间的信号转导。
用促生根际细菌（PGPR）解淀粉芽孢杆菌和荧光假单胞菌处理番茄植物表明，PP2A B'θ 亚基在对 PGPR 的反应中起作用。丛枝菌根真菌影响了在土壤中生长的植物中 B'θ 的转录本水平，这些植物具有典型的丛枝菌根。在所有测试条件下，B'φ 的转录本在植物根部都很少，其水平低于所有其他 PP2A 亚基的转录本。在 10 倍增强 B'φ 表达的转化番茄植物中，在蛭石中生长的植物的菌根化频率降低。此外，高 B'φ 表达与参与植物生长和菌根化的脱落酸和赤霉素反应有关。B'φ 过表达植物的生长活力较低，尽管果实大小正常，但每个果实的种子数量减少了 60%，与原始品种相比。
番茄根系中 B'θ 基因的表达受到有益微生物的强烈影响。对 B'φ 过表达番茄植物和已建立的番茄品种进行分析，证实了 B'φ 在生长和发育中的作用，以及在菌根化中的作用。
