LEAFY COTYLEDON 2: A Regulatory Factor of Plant Growth and Seed Development.

Boling Liu,Shijuan Liu,Ge Sun,Changju Liu

doi:10.3390/genes12121896

Abstract

Transcription factors are key molecules in the regulation of gene expression in all organisms. The transcription factor LEAFY COTYLEDON 2 (LEC2), which belongs to the DNA-binding protein family, contains a B3 domain. The transcription factor is involved in the regulation of important plant biological processes such as embryogenesis, somatic embryo formation, seed storage protein synthesis, fatty acid metabolism, and other important biological processes. Recent studies have shown that LEC2 regulates the formation of lateral roots and influences the embryonic resetting of the parental vernalization state. The orthologs of LEC2 and their regulatory effects have also been identified in some crops; however, their regulatory mechanism requires further investigation. Here, we summarize the most recent findings concerning the effects of LEC2 on plant growth and seed development. In addition, we discuss the potential molecular mechanisms of the action of the LEC2 gene during plant development.

Highlights

Seeds are the key means by which terrestrial plants adapt to changing environments in the processes of evolution and diversification, and seed development occurs after zygotic embryogenesis
In A. thaliana, the LEAFY COTYLEDON 2 (LEC2) gene was cloned and expressed ectopically, and the results revealed that it was preferentially expressed during embryogenesis and that it has the ability to induce the formation of somatic embryos [12]
The functional expression of the LEC2 gene in plants has resulted in significant progress in plant biology and the application of biotechnology to transgenic plants

Summary

Introduction

Seeds are the key means by which terrestrial plants adapt to changing environments in the processes of evolution and diversification, and seed development occurs after zygotic embryogenesis. When seeds are in the maturation stage of growth and development, energy reserves continue to accumulate, while the seeds gain desiccation tolerance [1] This process is strictly controlled at the transcription level, involving the AFL (ABI3/FUS3/LEC2) (ABA INSENSITIVE3/FUSCA3/LEAFY COTYLEDON 2) subfamily of B3 transcription factors (TFs). LEC2 contains two domains named B2 and B3 [13] It appears that the plant-specific B3 domain encoded by the LEC2 gene recognizes the conserved RY motif to transcriptionally regulate the expression of zygotic embryogenesis-specific genes and that it promotes somatic embryo formation at the maturation stage [12,14,15]. Through further in-depth exploration of the biological functions of LEC2, it was shown that the ectopic expression of LEC2 caused the accumulation of seed storage lipids and proteins in plant nutritive organs [23,24], further inducing vegetative cells to form somatic embryos without exogenous auxin or seed-specific genes being expressed in the leaves [12,23]. We discuss the impact of LEC2 on the growth and development of plants

The Effect of LEC2 on Plant Early Embryo Morphogenesis

The Effect of LEC2 on the Maturation of Plant Seeds

The LEC2 Gene Plays a Crucial Role in Somatic Embryogenesis

The Function of LEC2 during Other Plant Developmental Stages

Findings

Conclusions and Future Perspectives