Combined Transcriptome and Proteome Profiling Reveals Microbial Consortium mediated Growth Promotion and Reduction of Arsenic Burden and Toxicity in Rice (Oryza sativa L.)

In the present study, amelioration of arsenic (As) toxicity was performed by using Pseudomonas putida, a plant growth promoting rhizobacterium and As tolerant alga (Chlorella vulgaris) in rice (Oryza sativa). Arsenic being highly carcinogenic is a serious contaminant of food chain causes yield loss and several health risks. The growth promoting and As ameliorative potential of consortium was evident through improved growth of rice root hair and repaired structural anomalies of rice root. In present study, RNA seq. and proteome profiling were performed for in-depth understanding of consortium mediated amelioration and tolerance of As in rice plant. The study demonstrated that consortium of P. putida and C. vulgaris may alleviate As stress and improve growth of rice seedlings along with reduction in As levels. The down-regulation of As transporters (NIP, TIP and PIP) during As+P. putida+C.vulgaris suggested reduction of uptake and bioavailability of As to plants. Higher expression of WRKY gene (WRKY 28) and transporters of nutrient elements (ZIPs, YSL, COPT) in presence of consortium confirmed the reduction of As uptake as well as improved nutrient status of rice plant. Higher expression of regulatory elements like AUX/IAA, WRKY and MYB TFs during As+P. putida+C.vulgaris exposure was also observed. The down-regulation of defense responsive genes such as GST, PRX and GRX during As+P. putida+C.vulgaris exposure confirmed the reduction of As burden in rice plant in presence of consortium. The differential abundance of proteins involved in photosynthesis, energy metabolism, transport, signaling, defense and amino acid metabolism validated the growth promoting role of consortium during As stress in rice plant.

本研究通过施用植物促生根际菌恶臭假单胞菌（Pseudomonas putida）及耐砷藻类普通小球藻（Chlorella vulgaris），对水稻（Oryza sativa）的砷（As）毒害进行缓解。砷具有高致癌性，是严重的食物链污染物，可造成作物减产及多种健康风险。该联合体系的促生及砷毒害缓解潜力，可通过水稻根毛生长改善与根系结构异常修复得到验证。本研究通过RNA测序（RNA-seq）与蛋白质组分析，深入解析该联合体系介导的水稻砷毒害缓解与砷耐受机制。研究表明，恶臭假单胞菌与普通小球藻的联合体系可缓解水稻砷胁迫，促进幼苗生长并降低植株砷含量。在砷+恶臭假单胞菌+普通小球藻处理组中，砷转运蛋白（NIP、TIP及PIP）的表达下调，表明植物对砷的吸收及其生物利用度均有所降低。联合体系存在下，WRKY转录因子基因（WRKY 28）及营养元素转运蛋白（ZIPs、YSL、COPT）的表达上调，证实水稻砷吸收减少且营养状况得到改善。在砷+恶臭假单胞菌+普通小球藻处理下，还观察到AUX/IAA、WRKY及MYB等转录调控因子的表达上调。在砷+恶臭假单胞菌+普通小球藻处理下，谷胱甘肽S-转移酶（GST）、过氧化物酶（PRX）及谷氧还蛋白（GRX）等防御响应基因的表达下调，证实联合体系可降低水稻体内的砷负荷。参与光合作用、能量代谢、物质转运、信号传导、防御反应及氨基酸代谢的蛋白质丰度发生差异变化，验证了联合体系在水稻砷胁迫过程中的促生作用。