Kryukov A A, Gorbunova A O, Kudriashova T R, Ivanchenko O B, Shishova M F, Yurkov A P
All-Russia Research Institute for Agricultural Microbiology, Pushkin, St. Petersburg, Russia.
All-Russia Research Institute for Agricultural Microbiology, Pushkin, St. Petersburg, Russia Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia.
Vavilovskii Zhurnal Genet Selektsii. 2023 Jun;27(3):189-196. doi: 10.18699/VJGB-23-25.
Arbuscular mycorrhiza (AM) fungi receive photosynthetic products and sugars from plants in exchange for contributing to the uptake of minerals, especially phosphorus, from the soil. The identification of genes controlling AM symbiotic efficiency may have practical application in the creation of highly productive plant-microbe systems. The aim of our work was to evaluate the expression levels of SWEET sugar transporter genes, the only family in which sugar transporters specific to AM symbiosis can be detected. We have selected a unique "host plant-AM fungus" model system with high response to mycorrhization under medium phosphorus level. This includes a plant line which is highly responsive to inoculation by AM fungi, an ecologically obligate mycotrophic line MlS-1 from black medick (Medicago lupulina) and the AM fungus Rhizophagus irregularis strain RCAM00320, which has a high efficiency in a number of plant species. Using the selected model system, differences in the expression levels of 11 genes encoding SWEET transporters in the roots of the host plant were evaluated during the development of or in the absence of symbiosis of M. lupulina with R. irregularis at various stages of the host plant development in the presence of medium level of phosphorus available for plant nutrition in the substrate. At most stages of host plant development, mycorrhizal plants had higher expression levels of MlSWEET1b, MlSWEET3c, MlSWEET12 and MlSWEET13 compared to AM-less controls. Also, increased expression relative to control during mycorrhization was observed for MlSWEET11 at 2nd and 3rd leaf development stages, for MlSWEET15c at stemming (stooling) stage, for MlSWEET1a at 2nd leaf development, stemming and lateral branching stages. The MlSWEET1b gene can be confidently considered a good marker with specific expression for effective development of AM symbiosis between M. lupulina and R. irregularis in the presence of medium level of phosphorus available to plants in the substrate.
丛枝菌根（AM）真菌从植物中获取光合产物和糖分，以换取帮助植物从土壤中吸收矿物质，尤其是磷。鉴定控制AM共生效率的基因可能在创建高产植物-微生物系统方面具有实际应用价值。我们工作的目的是评估SWEET糖转运蛋白基因的表达水平，该基因家族是唯一能检测到AM共生特异性糖转运蛋白的家族。我们选择了一个独特的“宿主植物-AM真菌”模型系统，该系统在中等磷水平下对菌根形成反应强烈。这包括一个对AM真菌接种反应强烈的植物品系、来自黑苜蓿（Medicago lupulina）的生态专性菌根营养品系MlS-1以及AM真菌不规则球囊霉（Rhizophagus irregularis）菌株RCAM00320，该菌株在许多植物物种中效率较高。使用选定的模型系统，在宿主植物发育的不同阶段，在基质中存在可供植物营养的中等水平磷的情况下，评估了宿主植物根中11个编码SWEET转运蛋白的基因在与不规则球囊霉共生或不共生时的表达水平差异。在宿主植物发育的大多数阶段，与未接种AM真菌的对照相比，菌根植物中MlSWEET1b、MlSWEET3c、MlSWEET12和MlSWEET13的表达水平更高。此外，在菌根形成过程中，相对于对照，在第2和第3片叶发育阶段，MlSWEET11表达增加；在抽茎（分蘖）阶段，MlSWEET15c表达增加；在第2片叶发育、抽茎和侧枝阶段，MlSWEET1a表达增加。在基质中存在可供植物利用的中等水平磷的情况下，MlSWEET1b基因可以被确定为黑苜蓿与不规则球囊霉之间有效AM共生发育的具有特异性表达的良好标记。
