Impact of homologous overexpression of PR10a gene on improving salt stress tolerance in transgenic Solanum tuberosum

Abstract

Abiotic stresses severely affected crop productivity and considered to be a major yield limiting factor for crop plant. The tolerance to these stresses is a very complex phenomenon involving a wide array of molecular, biochemical and physiological changes in plant cells. Therefore, it is challenging to understand the molecular basis of abiotic stress tolerance to manipulate it for improving abiotic stress tolerance of major crops. Biotechnological approaches and genetic engineering including homologous gene overexpression can be implemented to understand gene functions under well-defined conditions. The Pathogenesis-related proteins (PR10) such as PR10a play multiple roles in biotic and abiotic stress tolerance and, hence, plant development. A PR10a gene from potato cv. Deseree was introduced into three cultivars of potato (Solanum tuberosum L.) by Agrobacterium tumefaciens-mediated genetic transformation. Transgenic plants were selected on a medium containing 1.0 mg/l phosphinothricin (PPT) and confirmed by polymerase chain reaction (PCR), herbicide (BASTA®) leaf paint assay, and Real-Time- quantitative PCR analyses (qPCR). All of the selected transformants showed completely tolerance to the application of PPT application. Experiments designed for testing salt tolerance revealed that there was enhanced salt tolerance of the transgenic lines in vitro in terms of morphological (plant FW, plant DW and plant height) and antioxidant activates as compared to the non-transgenic control plants. qRT-PCR showed that the expression of PR10a gene in the transgenic potato is higher than that in non-transgenic control under salt stress. The relative PR10a gene-expression patterns in the transgenic plants shed lights into the molecular response of homologues overexpressed PR10a potato to salt-stress conditions. The obtained results provide insights on the fact that PR10a plays a major role regarding salt stress tolerance in potato plants.