Transgenic Technology Can Accelerate Cotton Breeding: Transgenic ScALDH21 Cotton Significantly Improve Drought Tolerance in Southern and Northern Xinjiang

Abstract

Aldehyde dehydrogenases (ALDHs) contribute to cellular protection against oxidative stress. These enzymes are crucial to organisms’ ability to cope with environmental stress. The ALDH21 gene was introduced into upland cotton (Gossypium hirsutum L.) from desiccant-tolerant Syntrichia caninervis moss, created stable genetic transgenic lines. As a result, drought tolerance is increased and yield penalty is reduced in those transgenic lines. The first study to demonstrate overexpression of ALDH21 enhances drought tolerance in cotton under multi-location field experiments is presented here. Cotton genotypes containing ScALDH21 exhibit significant morphological, physiological, and economic benefits. ScALDH21 functions in the physiology of cotton plants to protect them by scavenging ROS and reducing osmotic stress. The yield of transgenic cotton in northern Xinjiang showed up to 10% improvement under full irrigation and up to 18% improvement in deficit irrigation conditions on fields with purple clay loam soils. Additionally, transgenic cotton can be grown in sandy loam soil in southern Xinjiang with an average yield increase of 40% on different irrigation levels in the desert-oasis ecotone. Using ScALDH21 as a candidate gene for cotton improvement in arid and semi-arid regions was demonstrated. In addition, we assessed different irrigation protocols and optimized irrigation methods with minimal water requirements for ScALDH21-transgenic cotton that could be used in production agriculture.