Understanding the mechanisms controlling appropriate xylem formation according to light conditions: Several genes share roles, control seedling growth

November 20, 2017

Potential to strengthen the water capacity of crops for improved productivity

NAIST and RIKEN CSRS researchers have clarified part of the mechanism by which plants respond to their light environment to create xylem vessel cells (used to transport water).

Xylem vessel cells are created by the actions of multiple genes in the VND family, which codes for transcription factors that act as master regulators of xylem vessel differentiation. However, the functional diversity of each gene in the VND family– seven in Arabidopsis, eight in rice and six in maize–remained unclear.

In this study, researchers succeeded in establishing an in vitro system, called as the KDB (cytokinin, auxin, brassinosteroid) system, in which the addition of the hormones converted leaf (cotyledon) cells into xylem vessel cells. Investigating the function of the genes driving this system, researchers were able to clarify that three genes, VND1, VND2 and VND3, are the major genes that create xylem vessel cells in the system. The function of these genes had remained unknown to this point. The researchers also demonstrated that these three genes are necessary to xylem vessel formation in cotyledons grown in the dark and that they control seedling growth in the light.

In the very early stages of seedling development, xylem vessel cells suited to the seedling's environment are created via specific VND genes, with the young plant actively harmonizing its own growth to match. Further development of this research offers the possibility of improved crop productivity via strengthening of plant water transport abilities. Since xylem cells are responsible for the generation of woody biomass—a next-generation energy resource–future research in this area can be expected to lead to technologies that increase woody biomass production and improve its usability.

Original article
Plant Physiology doi:10.1104/pp.17.00461
T. T. Tan, H. Endo, R. Sano, T. Kurata, M. Yamaguchi, M. Ohtani, T. Demura,
"Transcription factors VND1-3 contribute to cotyledon xylem vessel formation".
Misato Ohtani; Visiting Scientist
Taku Demura; Senior Visiting Scientist
Biomass Research Platform Team