Invited by Annual Review of Plant Biology, a research team led by Prof. FU Xiangdong at the Institute of Genetics and Developmental Biology (IGDB) of the Chinese Academy of Sciences (CAS) has reviewed the evolution of "Green Revolution" and highlighted the important role of DELLA proteins (consisting of GA INSENSITIVE, REPRESSOR OF GA1-3, RGA-LIKE1 (RGL1), RGL2, and RGL3) in balancing plant growth and metabolism.
 

 

 

The agricultural Green Revolution of the 1960s with an increased cultivation of semi-dwarf green revolution varieties (GRVs) has greatly enhanced crop yields to feed a growing world population. The semi-dwarf GRVs are resistant to the yield-reducing effect of 'lodging', but also require a high nitrogen fertilizer supply to achieve maximum yield potential. Further increase in fertilizer supplies is unlikely to be effective in improving yield because of diminishing returns and their deleterious impact on environmental problems. Therefore, the drive toward increased agricultural sustainability has raised the profile of reducing nitrogen fertilizer use in GRVs cultivation.
 

Both grain yield and nitrogen use efficiency are complex quantitative traits, which are controlled by quantitative trait loci and influenced by multiple environmental changes. Despite a great deal of research effort, to date only a few relevant genes have been identified to confer high yield and high nitrogen use efficiency, and the underlying molecular and regulatory mechanisms have remained an unsolved mystery. Therefore, it's intrinsically challenging to create new GRVs with both high yield and high nitrogen use efficiency by traditional breeding techniques.
 

In this review, the researchers summarized the recent research progress on how plants absorb, assimilate and utilize nitrate and ammonium, and how plants perceive and respond to nitrate signal. Finally, a new approach to enhance nitrogen use efficiency was proposed, which attempt to improve plant growth and carbon-nitrogen metabolism synergistically.
 

Prof. FU's team focuses on the basic and applied research on plant growth-metabolism coordination for sustainable agriculture. They have characterized several key genes regulating rice grain yield and nitrogen use efficiency.

"We here proposed a generation of new type GRVs with synergistic improvement in high yield and high nitrogen efficiency," said Prof. FU, "we hope we can realize a 'less input, more output' breeding strategy for sustainable agriculture."

This work was supported by the National Natural Science Foundation of China, the Youth Innovation Promotion Association, and the Strategic Priority Research Program of CAS.