Divergent regeneration‐competent cells adopt a common mechanism for callus initiation in angiosperms

• Published in: Regeneration Vol. 4; no. 3; pp. 132 - 139
• Main Authors: Hu, Bo, Zhang, Guifang, Liu, Wu, Shi, Jianmin, Wang, Hua, Qi, Meifang, Li, Jiqin, Qin, Peng, Ruan, Ying, Huang, Hai, Zhang, Yijing, Xu, Lin
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.06.2017; John Wiley and Sons Inc
• Subjects: Agricultural biotechnology; Agricultural practices; angiosperm; Angiosperms; Biotechnology; Callus; Cell culture; Cell fate; Cereals; Exhausts; Explants; Homeobox; Organs; Oryza sativa; plant regeneration; Regeneration; rice; Short Communication; Tissue culture; WOX11; WOX5; plant regeneration; rice; callus; WOX5; angiosperm; WOX11
• ISSN: 2052-4412; 2052-4412
• DOI: 10.1002/reg2.82

In tissue culture, the formation of callus from detached explants is a key step in plant regeneration; however, the regenerative abilities in different species are variable. While nearly all parts of organs of the dicot Arabidopsis thaliana are ready for callus formation, mature regions of organs in monocot rice (Oryza sativa) and other cereals are extremely unresponsive to tissue culture. Whether there is a common molecular mechanism beyond these different regenerative phenomena is unclear. Here we show that the Arabidopsis and rice use different regeneration‐competent cells to initiate callus, whereas the cells all adopt WUSCHEL‐RELATED HOMEOBOX 11 (WOX11) and WOX5 during cell fate transition. Different from Arabidopsis which maintains regeneration‐competent cells in mature organs, rice exhausts those cells during organ maturation, resulting in regenerative inability in mature organs. Our study not only explains this old perplexity in agricultural biotechnology, but also provides common molecular markers for tissue culture of different angiosperm species. Dicot Arabidopsis and monocot cereals have different types of regeneration‐competent cells, which all adopt the WOX11‐WOX5 pathway to initiate callus. Cereals exhaust regeneration‐competent cells during organ maturation and lose regenerative ability in mature organs.