Establishment of in vitro regeneration system and molecular analysis of early development of somatic callus in Capsicum chinense and Capsicum baccatum

Huangying Shu; Yu Zhang; Chengyao He; Muhammad Ahsan Altaf; Yuanyuan Hao; Daolong Liao; Lin Li; Caichao Li; Huizhen Fu; Shanhan Cheng; Guopeng Zhu; Zhiwei Wang

doi:10.3389/fpls.2022.1025497

Establishment of in vitro regeneration system and molecular analysis of early development of somatic callus in Capsicum chinense and Capsicum baccatum

Front Plant Sci. 2022 Nov 17:13:1025497. doi: 10.3389/fpls.2022.1025497. eCollection 2022.

Authors

Huangying Shu^{1

2

3}, Yu Zhang¹, Chengyao He¹, Muhammad Ahsan Altaf¹, Yuanyuan Hao¹, Daolong Liao^{1

4}, Lin Li¹, Caichao Li¹, Huizhen Fu^{1

2}, Shanhan Cheng^{1

2}, Guopeng Zhu^{1

2}, Zhiwei Wang^{1

2

3}

Affiliations

¹ Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, School of Horticulture, Hainan University, Haikou, China.
² Sanya Nanfan Research Institute, Hainan University, Sanya, China.
³ Hainan Yazhou Bay Seed Laboratory, Sanya, China.
⁴ Institute of Vegetables, Hainan Province Academy of Agricultural Sciences, Haikou, China.

Abstract

Regeneration is extremely important to pepper genetic development; however, the molecular mechanisms of how the callus reactivates cell proliferation and promotes cell reprogramming remain elusive in pepper. In the present study, C. baccatum (HNUCB81 and HNUCB226) and C. chinense (HNUCC22 and HNUCC16) were analyzed to reveal callus initiation by in vitro regeneration, histology, and transcriptome. We successfully established an efficient in vitro regeneration system of two cultivars to monitor the callus induction of differential genotypes, and the regenerated plants were obtained. Compared to C. chinense, there was a higher callus induction rate in C. baccatum. The phenotype of C. baccatum changed significantly and formed vascular tissue faster than C. chinense. The KEGG enrichment analysis found that plant hormone transduction and starch and sucrose metabolism pathways were significantly enriched. In addition, we identified that the WOX7 gene was significantly up-regulated in HNUCB81 and HNUCB226 than that in HNUCC22 and HNUCC16, which may be a potential function in callus formation. These results provided a promising strategy to improve the regeneration and transformation of pepper plants.

Keywords: Capsicum baccatum; Capsicum chinense; WGCNA; histology; in vitro regeneration transcriptome; somatic callus.