1. The pigeon pea CcCIPK14‐CcCBL1 pair positively modulates drought tolerance by enhancing flavonoid biosynthesis
- Author
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Li-Tao Wang, Dong Meng, Zhihua Song, Qing Yang, Rohul Amin, Biying Dong, Lili Niu, Hanghang Li, Hongyan Cao, and Yu-Jie Fu
- Subjects
0106 biological sciences ,0301 basic medicine ,Drought tolerance ,Flavonoid ,Gene Expression ,Plant Science ,Genetically modified crops ,Protein Serine-Threonine Kinases ,Plant Roots ,01 natural sciences ,03 medical and health sciences ,Cajanus ,chemistry.chemical_compound ,Gene Expression Regulation, Plant ,Stress, Physiological ,Two-Hybrid System Techniques ,Genetics ,Gene family ,Calcium Signaling ,Apigenin ,Phosphorylation ,Gene ,Plant Proteins ,Flavonoids ,chemistry.chemical_classification ,biology ,Calcium-Binding Proteins ,fungi ,food and beverages ,Cell Biology ,Plants, Genetically Modified ,biology.organism_classification ,Genistein ,Isoflavones ,Droughts ,030104 developmental biology ,Flavonoid biosynthesis ,chemistry ,Biochemistry ,RNA Interference ,010606 plant biology & botany - Abstract
Calcineurin B-like (CBL)-interacting protein kinases (CIPKs) play a central role in Ca2+ signalling and promote drought tolerance in plants. The CIPK gene family in pigeon pea (Cajanus cajan L.), a major food crop affected by drought, has not previously been characterised. Here, we identified 28 CIPK genes in the pigeon pea genome. Five CcCIPK genes were strongly upregulated in roots upon drought treatment and were selected for further characterisation. Overexpression of CcCIPK13 and CcCIPK14 increased survival rates by two- to three-fold relative to controls after 14 days of drought. Furthermore, the three major flavonoids, genistin, genistein and apigenin, were significantly upregulated in the same transgenic plants. Using CcCIPK14 as bait, we performed a yeast two-hybrid screen and identified six interactors, including CcCBL1. CcCIPK14 exhibited autophosphorylation and phosphorylation of CcCBL1 in vitro. CcCBL1-overexpressed plants displayed higher survival rates upon drought stress as well as higher expression of flavonoid biosynthetic genes and flavonoid content. CcCIPK14-overexpressed plants in which CcCBL1 transcript levels were reduced by RNA interference had lower survival rates, which indicated CcCBL1 in the same pathway as CcCIPK14. Together, our results demonstrate a role for the CcCIPK14-CcCBL1 complex in drought stress tolerance through the regulation of flavonoid biosynthesis in pigeon pea.
- Published
- 2021