Analysis of Nicotiana tabacum PIN genes identifies NtPIN4 as a key regulator of axillary bud growth |
| |
| Authors: | Xiaodong Xie Guangyong Qin Ping Si Zhaopeng Luo Junping Gao Xia Chen Jianfeng Zhang Pan Wei Qingyou Xia Fucheng Lin Jun Yang |
| |
| Institution: | 1. China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China;2. College of Physical Engineering, Zhengzhou University, Zhengzhou, China;3. Centre for Plant Genetics and Breeding, School of Plant Biology, The University of Western Australia, Crawley, Australia;4. State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China |
| |
| Abstract: | The plant‐specific PIN‐FORMED (PIN) auxin efflux proteins have been well characterized in many plant species, where they are crucial in the regulation of auxin transport in various aspects of plant development. However, little is known about the exact roles of the PIN genes during plant development in Nicotiana species. This study investigated the PIN genes in tobacco (Nicotiana tabacum) and in two ancestral species (Nicotiana sylvestris and Nicotiana tomentosiformis). Genome‐wide analysis of the N. tabacum genome identified 20 genes of the PIN family. An in‐depth phylogenetic analysis of the PIN genes of N. tabacum, N. sylvestris and N. tomentosiformis was conducted. NtPIN4 expression was strongly induced by the application of exogenous indole‐3‐acetic acid (IAA), but was downregulated by the application of ABA, a strigolactone analogue, and cytokinin, as well as by decapitation treatments, suggesting that the NtPIN4 expression level is likely positively regulated by auxin. Expression analysis indicated that NtPIN4 was highly expressed in tobacco stems and shoots, which was further validated through analysis of the activity of the NtPIN4 promoter. We used CRISPR‐Cas9 technology to generate mutants for NtPIN4 and observed that both T0 and T1 plants had a significantly increased axillary bud growth phenotype, as compared with the wild‐type plants. Therefore, NtPIN4 offers an opportunity for studying auxin‐dependent branching processes. |
| |
| Keywords: | |
|
|
