Regulation of cell reprogramming by auxin during somatic embryogenesis
- PDF / 449,162 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 57 Downloads / 231 Views
aBIOTECH
REVIEW
Regulation of cell reprogramming by auxin during somatic embryogenesis Li Ping Tang1 , Xian Sheng Zhang1 , Ying Hua Su1& 1
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an 271018, Shandong, China
Received: 11 March 2020 / Accepted: 21 August 2020 / Published online: 3 September 2020
Abstract
How somatic cells develop into a whole plant is a central question in plant developmental biology. This powerful ability of plant cells is recognized as their totipotency. Somatic embryogenesis is an excellent example and a good research system for studying plant cell totipotency. However, very little is known about the molecular basis of cell reprogramming from somatic cells to totipotent cells in this process. During somatic embryogenesis from immature zygotic embryos in Arabidopsis, exogenous auxin treatment is required for embryonic callus formation, but removal of exogenous auxin inducing endogenous auxin biosynthesis is essential for somatic embryo (SE) induction. Ectopic expression of specific transcription factor genes, such as ‘‘LAFL’’ and BABY BOOM (BBM), can induce SEs without exogenous growth regulators. Somatic embryogenesis can also be triggered by stress, as well as by disruption of chromatin remodeling, including PRC2-mediated histone methylation, histone deacetylation, and PKL-related chromatin remodeling. It is evident that embryonic identity genes are required and endogenous auxin plays a central role for cell reprogramming during the induction of SEs. Thus, we focus on reviewing the regulation of cell reprogramming for somatic embryogenesis by auxin.
Keywords Somatic embryogenesis, Auxin, Cell reprogramming, Transcription factors, Chromatin remodeling
INTRODUCTION Single-celled zygotes of both plants and animals have the capacity to form a whole organism and are considered totipotent. However, only plants have the capacity to regenerate whole plants from differentiated somatic cells of a variety of tissues through in vitro culture, displaying remarkable developmental plasticity. Gottleib Haberlandt (1854–1945) proposed the concept of plant totipotency in 1902, based on the cell theory of Schleiden (1838) and Schwann (1839). At that time, Haberlandt hypothesized that entire plants could be generated by culturing isolated somatic cells. However, there was not any experimental evidence to support the hypothesis for more than half a century. Then in 1958, & Correspondence: [email protected] (Y. H. Su)
Steward showed that entire plants could be regenerated from segments of the differentiated secondary phloem of a carrot (Steward et al. 1958), thus demonstrating the remarkable totipotency of plant cells. Somatic embryogenesis is an important model system for plant regeneration and is believed to be the strongest proof for the totipotency of plant somatic cells. Somatic embryogenesis refers to the process of asexual reproduction of somatic cells leading to the development of a new individual from vegetative tissues, such as leaf protoplast
Data Loading...
