Method for improving salt tolerance and drought resistance of cotton by increasing synthesis capability of betaine

Abstract

The invention discloses a method for improving salt tolerance and drought resistance of cotton by increasing synthesis capability of betaine. A plant expression vector pCAMBIA1300-GhPEAMT-betA-EPSP is constructed by recombining a choline dehydrogenase gene betA and a phosphoethanolamine n-methyltransferase gene GhPEAMT by the aid of expression vectors pCAMBIA1300-GhPEAMT-EPSP and pCAMBIA1300-betA-als and then is transferred into a cotton cell for efficient expression, and a transgenic plant is regenerated; resistant seedlings are obtained by spraying herbicide glyphosate at the seedling stage, and a transgene homozygote is screened from a resistant plant and descendants thereof in combination of a conventional molecular detection technology; the transgenic homozygote with salt tolerance and drought resistance remarkably improved is screened and identified from a saline and alkaline pond or a drought shed, and a new germ plasm for breeding of salt-tolerant and drought-resistant cotton is obtained by increasing the synthesis capability of betaine. By means of the method, a metabolic pathway for synthesizing glycine betaine with phosphoethanolamine as a raw material is created, and an experiment proves that the salt tolerance and the drought resistance of the transgenic cotton are remarkably improved.

Description

technical field [0001] The invention relates to a method for improving cotton salt tolerance and drought resistance by increasing betaine synthesis ability, which belongs to the field of plant genetic engineering. Background technique [0002] Soil salinization and drought are one of the main threats to agricultural food production. Since plants are fixed in the environment and cannot move independently, in order to cope with stresses such as temperature, salinity, drought, and heavy metals, plants have a variety of coping mechanisms to adapt to diverse abiotic stresses. Among the many mechanisms to cope with drought and high-salt stress, an important strategy is that cells synthesize compatible compounds to help plants survive under drought and high-salt stress. These synthetic substances are called compatible compounds (Rhodes D&Hanson AD.Ann.Rev.Plant Physiol.Plant Mol.Biol. ., 1993, 44:357-384). Betaine is one of the better biocompatible substances (Raza et al. Plant ...

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Problems solved by technology

However, it was found in transgenic tobacco, Arabidopsis and rapeseed that if the transgenic plants could obtain exogenous choline, the accumulation of betaine in the transgenic plants would increase (Huang, et al.. Plant Physiol., 2000, 122(3 ):747-756; Nuccio, et al.Plant J.1998,16(4):487-496.), so these transgenic plants do not have a high concentration accumulation may be due to the supply of the substrate choline required for betaine synthesis is limited due to limit

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