The EXP1 gene encodes expansin, which has the ability to loosen the plant cell wall. The soybean expansin gene GmEXP1 is activated specifically during the root elongation process, and thus it plays important roles in root development. During the drought period, changes in pressure within the cell and the fast development of the root allow plants to collect water from deep soil, which in turn helps plants grow and develop. | Turkish Journal of Botany Turk J Bot (2015) 39: 988-995 © TÜBİTAK doi: Research Article Overexpression of a soybean expansin gene, GmEXP1, improves drought tolerance in transgenic tobacco 1 2 3 2 2 3, Thanh Son LO , Hoang Duc LE , Vu Thanh Thanh NGUYEN , Hoang Ha CHU , Van Son LE , Hoang Mau CHU * 1 Tay Bac University, Son La, Vietnam 2 Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam 3 Department of Genetics and Modern Biology, Thai Nguyen University, Thai Nguyen, Vietnam Received: Accepted/Published Online: Printed: Abstract: The EXP1 gene encodes expansin, which has the ability to loosen the plant cell wall. The soybean expansin gene GmEXP1 is activated specifically during the root elongation process, and thus it plays important roles in root development. During the drought period, changes in pressure within the cell and the fast development of the root allow plants to collect water from deep soil, which in turn helps plants grow and develop. In this study, we have successfully cloned and generated a GmEXP1 construct expressing recombinant expansin protein in tobacco plants. GmEXP1 is expressed in transgenic tobacco plants and passed on to the next generation. The transgenic tobacco plants have improved drought tolerance, which is demonstrated in both the length and volume of roots. From these promising results, we applied the same approach to generate drought-tolerant plants. Key words: Agrobacterium-mediated transformation, expansin, GmEXP1 gene, loosening of cell wall, root elongation, soybean 1. Introduction Drought stress is one of the most important yield-reducing factors in crop production. The molecular basis of drought tolerance mechanisms in plants have attracted interest: one study aimed to identify the protein profiles and dehydrin accumulation in seven varieties of local Indonesian soybeans (Arumingtyas et .
