球囊霉素相关土壤蛋白与根系形态的相关性研究

The relationships between glomalin-related soil protein and root morphology

球囊霉素相关土壤蛋白(GRSP)是丛枝菌根(AM)真菌菌丝分泌的糖蛋白,能够促进土壤团聚体的形成。多种因素影响GRSP的产量,植物根系形态是否通过碳素竞争机制影响GRSP产量目前尚不清楚。以Glomus mosseae的两个生态型菌株和红三叶草Trifolium repense为试材,通过砂培试验探讨宿主的根系形态与GRSP产量的相关性。发现接种AM真菌导致宿主细根的比例降低,粗根的比例增加,但对总根长和根表面积没有影响;侵染率和菌丝长度随着时间的延长而增加,菌株之间存在显著差异;接种AM真菌导致GRSP产量显著提高;GRSP产量与根系形态没有显著的相关性,但是与侵染率和菌丝长度显著相关。结果表明,尽管宿主根系形态建成和AM真菌都对碳素具有竞争关系,但是前者并没有抑制GRSP的形成,可能存在根系碳素分配的自调控机制。

Glomalin-related soil protein （GRSP） is a glycoprotein secreted from the hyphae of arbuscular mycorrhizal （AM） fungi, and it can promote the formation of soil aggregates. Production of GRSP is affected by many factors. It is presently not clear if host root morphology affects GRSP production through competition for carbon source. In this study, two ecotypes of Glomus mosseae and red clover （Trifolium repense） were taken as biological materials to investigate the relationship between root morphology and GRSP production in sand culture. The test results indicated that AM inoculation increased the proportion of fine roots, while decreased the proportion of coarse roots, but did not affect the total root length and rootsurface area. Colonization of AM fungi and hyphal length increased along with time extending, and showed significant difference between the strains. Inoculation of AM fungi increased the GRSP production. The correlation analysis indicated that GRSP production was not related to root morphology, but significantly correlated with AM fungi colonization and hyphal length. It is suggested that the establishment of root morphology didn＇t inhibit GRSP production although the AM fungi and host plant competed for carbon source. A possible auto-regulation mechanism might be present for the partitioning carbon source in mycorrhiza.