Abstract:

【Objective】 Nitraria tangutorum is a pioneer plant for the soil desertification and salinization control. It is adaptable to high salt and drought conditions. The CBL gene plays an important role in plant stress responses and development as it encodes a calcium ion receptor. Here, we aimed to clone and express CBL in N. tangutorum, which laid a foundation for the study of CBL gene family responses stress and the molecular mechanism of stress resistance of N. tangutorum. 【Method】 We designed specific primers based on N. tangutorum transcriptome data to clone two CBL genes that were further characterized using bioinformatics tools, and their subcellular localization was determined. We investigated the expression of the gene in N. tangutorum under CBL-base salt stress by using real-time quantitative PCR. 【Result】 The NtCBL1 and NtCBL2 genes of N. tangutorum were cloned and identified. The cDNA of NtCBL1 was 642 bp long and encoded 213 amino acids. The relative molecular weight of the protein was 52.77 ku, and the molecular formula was C_{1 971}H_{3 302}N₆₄₂O₈₃₆S₁₀₆. The cDNA of NtCBL2 was 681 bp long and encoded 213 amino acids. The relative molecular weight of the protein was 26.1 ku, and the molecular formula was C_{1 179}H_{1 832}N₂₉₈O₃₅₆S₇. We predicted that the NtCBL1 and NtCBL2 proteins localized at the cell membrane. Under the salt stress, drought stress and cold stress, the expression of NtCBL1 and NtCBL2 changed by various degrees, but NtCBL1 gene was significantly up-regulated under salt and drought stress, and NtCBL2 gene was significantly up-regulated under cold stress. 【Conclusion】 The NtCBL1 and NtCBL2 genes contribute to the adaptation of N. tangutorum to the salt stress. The NtCBL1 gene may be involved in the response of N. tangutorum to the salt as well as drought stress, and the NtCBL2 gene plays a certain role under cold stress.

Key words: Nitraria tangutorum, CBL gene, salt stress, drought stress, gene cloning, gene expression