Investigation On The Effect Of Tibetan Wild Barley HsCBL8Gene On Salt Tolerance In Transgenic Rice

Salinity stress affects crop production worldwide, particularly by limiting plant growth and reducing potential yield. Rice is one of the most important cereal crops in China, which is seriously restricted by increasing soil salinity. Breeding salt-tolerance rice varieties using biotechnology is an effective approach to solve this problem. The innovation and expansion of gene resources are of great importance in modern breeding systems. The Tibet Plateau is one of the centers of domestication of cultivated barley. Recent investigations revealed an abundant germplasm resources of wild barley in this area, and the exploration of these precious germplasm resources can lay a solid foundation for producing stress-tolerance crops. The family of calcineurin B-like (CBL) proteins represents a plant-specific calcium sensors in plants, which accurately decodes the calcium signals and efficiently regulates the downstream responses to environmental stresses by interacting with the family of CBL-interacting protein kinases (CIPKs). In the recent study, the ProHsCBL8-GUS and35S-HsCBL8molecular cassette were constructed and used for Arabidopsis and rice transformation. The function of HsCBL8in response to salt-stress was carefully studied. The major results obtained from this research are summarized as the followings:1. Comparison of morphological appearance and Na+/K-ratio between XZ166(the accession where HsCBL8was cloned from) and CM72under salt stress condition showed that XZ166is more tolerance to salinity. The CBL8gene responds more efficiently to salt stress in XZ166.2. The Arabidopsis plants transformed with ProHsCBL8-GUS were treated with ABA, drought, NaCl, and cold stress, the GUS activity determination revealed that the expression of HsCBL8is stress inducible.3.35S-HSCBL8was transformed into rice calli by Agrobacterium tumefaciens-mediated transformation. Transgenic lines were identified by PCR, Southern blotting and reverse transcription PCR, and homozygotic lines of transgenic rice were identified.4. Comparison of morphological appearance and salt tolerance-related parameters between T3transgentic lines and the non-transgenic plant ZH11under salt stress indicated that T3lines overexpressing HsCBL8were characterized by more tolerance to salt.