Role of Sulphate Transporter(PiSulT)of Endophytic FungusSerendipita indicain Plant Growth and Development

Abstract

ABSTRACTSulfur is an important macronutrient required for the growth, development of plants and is a key component of many metabolic pathways. We have functionally characterized a high-affinity sulphate transporter (PiSulT) from an endophytic fungusSerendipita indica. ThePiSulTbelongs to the major facilitator superfamily (MFS) of membrane transporter. ThePiSulTfunctionally complements the yeast sulphate transporter mutant HK14.PiSulTis a high-affinity sulphate transporter, havingKm15μM. We found enhanced expression ofPiSulTin external fungal hyphae which helps the fungus in the acquisition of sulphate from the soil. When knockdown (KD)-PiSulT-P.indicacolonized with the plant, it results in an 8-fold reduction in the transfer of sulphate to the colonized plants as compared to the plants colonized with the WTS. indica, which suggests thatPiSulTis playing a role in sulphate transfer from soil to host plant. Further, plants colonized with the WTS. indicawere found to be healthy in comparison to the plants colonized with the KD-PiSulT-P.indica. Additionally,S. indicacolonization provides a positive effect on total sulfur content and on plant metabolites like sulfate ions and glutathione, particularly under low sulphate condition. We observed that the expression of sulfur assimilation pathway genes ofS. indicaand plant is dependent on the availability of sulphate and on the colonization with the plant. Our study highlights the importance ofPiSulTin the improvement of sulfur nutrition of host plant particularly under low sulphate condition and in plant growth development. This study will open new vistas to useS. indicaas a bio-fertilizer in the sulphate deficient field to improve crop production.One-Sentence SummaryHigh-affinity sulphate transporter ofSerendipita indica(PiSulT) transfer sulphate from soil to plant under low sulphate condition and improve plant growth and development.