DIVERSITY OF A PHOSPHATE TRANSPORTER GENE AMONG SPECIES AND ISOLATES OF ARBUSCULAR MYCORRHIZAL FUNGI. AMF diversity within ribosomal and phosphate transporter gene sequences

Arbuscular mycorrhizal fungi (AMF) are a key group of beneficial soil microorganisms, establishing a mutualistic symbiosis with the roots of most land plants. The molecular markers usually used for their characterization are mainly based on informative regions of nuclear rDNA (SSU-ITS-LSU), but protein-encoding genes have also been proposed. Within functional genes, those encoding for phosphate transporters (PT) are particularly important in AMF, given their primary ability to uptake Pi from soil, and to differentially affect plant phosphate nutrition. In this work, we investigated the genetic diversity of PT1gene sequences and sequences of the taxonomically relevant SSU-ITS-LSU region in two isolates of the species Funneliformis coronatus, three isolates of the species Funneliformis mosseae and two species of the genus Rhizoglomus, originated from geographically distant areas and cultured in vivo. Our results showed that, while ribosomal gene sequences successfully differentiated AMF genera and species, partial PT1 sequences allowed to highlight also intraspecific diversity among F. mosseae and F. coronatus isolates. The study of functional genes related to the uptake of key mineral nutrients for the assessment of AMF diversity represents a key step in the selection of efficient isolates to be used as inocula in sustainable agriculture.

丛枝菌根真菌（Arbuscular mycorrhizal fungi, AMF）是一类关键的有益土壤微生物，可与绝大多数陆生植物的根系建立互惠共生关系。目前用于其分类鉴定的分子标记多以细胞核核糖体DNA（SSU-ITS-LSU）的信息区域为基础，但也有研究提出可采用蛋白编码基因作为标记。在功能基因中，编码磷酸盐转运蛋白（phosphate transporters, PT）的基因对AMF而言尤为关键，因其能够直接从土壤中摄取Pi，并对植物的磷素营养产生差异化影响。本研究针对两株冠状漏斗囊霉（Funneliformis coronatus）分离株、三株摩西漏斗囊霉（Funneliformis mosseae）分离株以及两株根孢囊霉属（Rhizoglomus）物种的样本，分析了PT1基因序列与分类学相关的SSU-ITS-LSU区域序列的遗传多样性；所有供试样本均采自地理距离较远的区域，并完成了活体培养。研究结果表明，核糖体基因序列可有效区分AMF的属与物种，而部分PT1序列则可进一步揭示摩西漏斗囊霉与冠状漏斗囊霉分离株间的种内遗传多样性。针对与关键矿质养分摄取相关的功能基因开展研究以评估AMF多样性，是筛选可应用于可持续农业的高效接种菌株的核心环节。