Reddy Chinreddy Subramanyam, Cho Min, Kaul Tanushri, Joeng Jin Tae, Kim Kang Min
Division of Biotechnology, College of Environmental and Bio Resource Science, Chonbuk National University, Iskan, 570-572, Republic of Korea.
Department of Biology, West Virginia State University, 141 Hamblin Hall, Institute, WV, 25112-1000, USA.
J Genet Eng Biotechnol. 2023 Jan 25;21(1):8. doi: 10.1186/s43141-022-00457-7.
Cadmium is a non-essential, third largest heavy metal contaminant with long retention time that poses environmental hazards. It emanating majorly from industrial processes and phosphate fertilizers. Cadmium is effortlessly assimilated by plants and leads to yield loss. Henceforth, identification of mechanisms to attenuate the heavy metal toxicity in crops is beneficial for enhanced yields.
Beneficial soil bacteria have been known to combat both biotic and abiotic stress, thereby promoting plant growth. Amongst them, Pseudomonas fluorescens has been shown to enhance abiotic stress resistance in umpteen crops for instance maize and groundnut. Here, we investigated the role of P. fluorescens in conferring cadmium stress resistance in Arabidopsis thaliana. In silico analysis of PCR2 gene and promoter revealed the role, in cadmium stress resistance of A. thaliana. Real-time expression analysis employing qRT-PCR ratified the upregulation of AtPCR2 transcript under cadmium stress up to 6 folds. Total leaf (50%), biomass (23%), chlorophyll content (chlorophyll-a and b 40%, and 36 %) silique number (50%), and other growth parameters significantly improved on bacterial treatment of the 2mM Cd-stressed plants.
Moreover, generated 35s-promoter driven AtPCR2 over-expressing transgenic lines that exhibited resistance to cadmium and other heavy metal stress. Taken together, a crucial interplay of P. fluorscens mediated enhanced expression of AtPCR2 significantly induced cadmium stress resistance in Arabidopsis plants.
镉是一种非必需的、滞留时间长的第三大重金属污染物，会对环境造成危害。它主要来自工业生产过程和磷肥。镉很容易被植物吸收，导致产量损失。因此，确定减轻作物重金属毒性的机制有利于提高产量。
已知有益土壤细菌可对抗生物和非生物胁迫，从而促进植物生长。其中，荧光假单胞菌已被证明能增强多种作物（如玉米和花生）的非生物胁迫抗性。在此，我们研究了荧光假单胞菌在拟南芥中赋予镉胁迫抗性的作用。对PCR2基因和启动子的电子分析揭示了其在拟南芥镉胁迫抗性中的作用。采用qRT-PCR的实时表达分析证实，在镉胁迫下AtPCR2转录本上调高达6倍。对2mM镉胁迫的植物进行细菌处理后，总叶面积（50%）、生物量（23%）、叶绿素含量（叶绿素a和b分别为40%和36%）、角果数（50%）和其他生长参数均有显著改善。
此外，构建了35s启动子驱动的AtPCR2过表达转基因株系，该株系对镉和其他重金属胁迫具有抗性。综上所述，荧光假单胞菌介导的AtPCR2表达增强之间的关键相互作用显著诱导了拟南芥植株对镉胁迫的抗性。
