Alireza Abbasi1, Meysam Malekpour2, Sajjad Sobhanverdi2. 1. Department of Agronomy and Plant Breeding, Faculty of Agricultural Science and Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Islamic Republic of Iran. rezabbasi@ut.ac.ir. 2. Department of Agronomy and Plant Breeding, Faculty of Agricultural Science and Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Islamic Republic of Iran.
Abstract
BACKGROUND: Expansins are cell wall proteins loosening plant cell in pH-dependent manner. This study aimed to investigate the role of AtEXPA18 in different morphological, physiological, and cellular responses of transgenic tobacco plants to moderate and severe drought stress. METHODS AND RESULTS: Previously synthesized AtEXPA18 gene construct was successfully transferred to the tobacco plants through an agrobacterium-mediate transformation system. Upon obtaining the second generation, tobacco transgenic plants were confirmed by conventional polymerase chain reaction (PCR) technique alongside reverse transcription PCR (RT-PCR) using specific primers. Under drought stress, the transgenic lines showed remarkable growth and significantly improved based on morphological traits such as height and stem diameter, leaf area, leaf number, root dry weight, and Abscisic acid levels of leaves compared control plants. As a result, the Cytokinin content of transgenic plants has increased under severe stress levels. Notably, the area's expansion for abaxial epidermal cells under the microscope confirmed in transgene cells compared with the -transgene cells. CONCLUSION: These results, altogether, could support the AtEXPA18 gene implication in cell expansion and improving tolerance capacity of transgenic crops under drought stress.
BACKGROUND: Expansins are cell wall proteins loosening plant cell in pH-dependent manner. This study aimed to investigate the role of AtEXPA18 in different morphological, physiological, and cellular responses of transgenic tobacco plants to moderate and severe drought stress. METHODS AND RESULTS: Previously synthesized AtEXPA18 gene construct was successfully transferred to the tobacco plants through an agrobacterium-mediate transformation system. Upon obtaining the second generation, tobacco transgenic plants were confirmed by conventional polymerase chain reaction (PCR) technique alongside reverse transcription PCR (RT-PCR) using specific primers. Under drought stress, the transgenic lines showed remarkable growth and significantly improved based on morphological traits such as height and stem diameter, leaf area, leaf number, root dry weight, and Abscisic acid levels of leaves compared control plants. As a result, the Cytokinin content of transgenic plants has increased under severe stress levels. Notably, the area's expansion for abaxial epidermal cells under the microscope confirmed in transgene cells compared with the -transgene cells. CONCLUSION: These results, altogether, could support the AtEXPA18 gene implication in cell expansion and improving tolerance capacity of transgenic crops under drought stress.