Due to rising temperatures and rain, recent news reports multiple occurrences of duckweed outbreak. Duckweed is considered a promising source of energy because of its high starch content and rapid growth rate. Starch accumulation in duckweed involves complex processes that depend on the balanced expression of genes controlled by various environmental and endogenous factors.

The research team led by Dr. ZHOU Gongke from Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences (CAS), announced that they found the key gene of the efficient starch accumulation in duckweed using transcriptome, metabolics and related enzyme activity determination method.

Researchers analyzed the transcriptomic profiles and metabolite patterns of duckweed (Lemna aequinoctialis 6000) during a seven-day time course under nitrogen starvation. Differentially expressed genes (DEGs) were identified and categorized as various functional classifications and nitrogen starvation-related metabolic metabolisms, which were further validated by examining specific enzyme activities. The results demonstrate the feasibility of using transcriptome data with a next-generation sequencing (NGS) method to identify interesting pathways and potential target genes, which could serve as excellent candidates for functional genomics studies and metabolic engineering to improve the production of next-generation biofuels in duckweed.

Starch metabolism is a complex process triggered by changes in the levels of numerous transcripts and metabolites. The research results presented the dynamic transcriptome changes in Lemna aequinoctialis 6000 and reveal the complex mechanisms in starch accumulation. The genes identified as being involved in starch metabolism represent excellent candidates for further genetic improvement of starch production in duckweed.

The related findings were published in Journal of Biotechnology for Biofuels. This study was funded by the National Key Technology Research and Development Program of China (2015BAD15B01), National Natural Science Foundation of China (No. 31600285,No.U1632140), major science and technology projects of Shandong province (2015ZDJS03002, 2016ZDJS10A04, 2016GNC113020).

Figure: A hypothetical model of pathways related to carbohydrate metabolism during nitrogen starvation in L. aequinoctialis. (Image by YU Changjiang)

(Text by YU Changjiang)

Contact:

Prof. Zhou Gongke, Ph.D., Principal Investigator
QIBEBT, CAS
(http://english.qibebt.cas.cn/)
Qingdao, Shandong, 266101, China
Tel: +86-0532-80662731
E-mail: zhougk@qibebt.ac.cn