Jatropha curcas ortholog of tomato MADS-box gene 6 (JcTM6) promoter exhibits floral-specific activity in Arabidopsis thaliana

Jing-Xian Wang; Xin Ming; Yan-Bin Tao; Zeng-Fu Xu

doi:10.7717/peerj.9827

Jatropha curcas ortholog of tomato MADS-box gene 6 (JcTM6) promoter exhibits floral-specific activity in Arabidopsis thaliana

PeerJ. 2020 Sep 17:8:e9827. doi: 10.7717/peerj.9827. eCollection 2020.

Authors

Jing-Xian Wang^{1

2}, Xin Ming^{1

2}, Yan-Bin Tao^{2

3}, Zeng-Fu Xu^{2

3}

Affiliations

¹ School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China.
² CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Innovation Academy for Seed Design, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, China.
³ Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, China.

Abstract

Background: Jatropha curcas L., a perennial oilseed plant, is considered as a promising feedstock for biodiesel production. Genetic modification of flowering characteristics is critical for Jatropha breeding. However, analysis of floral-specific promoters in Jatropha is limited.

Methods: In this study, we isolated the Jatropha ortholog of TM6 (JcTM6) gene from Jatropha flower cDNA library and detected the expression pattern of JcTM6 gene by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). We isolated a 1.8-kb fragment from the 5' region of the JcTM6 gene and evaluated its spatiotemporal expression pattern in Arabidopsis using the β-glucuronidase (GUS) reporter gene and Arabidopsis ATP/ADP isopentenyltransferase 4 (AtIPT4) gene, respectively.

Results: JcTM6 was identified as a flower-specific gene in Jatropha. As expected, JcTM6 promoter was only active in transgenic Arabidopsis flowers with the strongest activity in stamens. Moreover, JcTM6:AtIPT4 transgenic Arabidopsis showed a phenotype of large flowers without any alterations in other organs. Furthermore, deletion of the region from -1,717 to -876 bp resulted in the disappearance of promoter activity in stamens but an increase in promoter activity in young leaves, sepals, and petals. Deletion analysis suggests that the -1,717- to -876-bp promoter fragment contains regulatory elements that confer promoter activity in stamens and inhibit activity in young leaves, sepals, and petals.

Keywords: Arabidopsis; Flower; Physic nut; Promoter; TM6.

Grants and funding

This work was supported by the Natural Science Foundation of Yunnan Province (2016FB048), the National Natural Science Foundation of China (31370595) and the Programme of the Chinese Academy of Sciences (kfj-brsn-2018-6-008 and 2017XTBG-T02). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.