Cyperus esculentus (yellow nutsedge or tiger nut), a representative species of Cyperaceae(the third largest family of monocots), is a unique plant with notably high oil accumulation in its mature tubers. The characteristics of the oil-rich tubers in C. esculentus have led several groups to identify key genes for oil biosynthesis. However, few studies have reported the full-length transcriptomes of Cyperus plants.

In a study published in Plant Science, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) investigated the genomic and transcriptomic features of C. esculentus and its related species to reveal potential genes and regulatory networks associated with tuber oil accumulation.

The researchers sequenced and assembled the genome of C. esculentus at the contig level, obtaining the first relatively complete genome sequence of this species as the reference genome. They subsequently obtained two full-length transcriptomes of C. esculentus and its close relative C. rotundus, through a combination of second- and third-generation sequencing technologies.

They then compared high-quality transcriptomes in 36 tissues among high-oil, medium-oil, and low-oil C. esculentus and low-oil C. rotundus to identify potential genes and regulatory networks associated with tuber oil accumulation.

They identified tuber-specific genes in two C. esculentus cultivars. They also found that genes involved in fatty acid (FA) biosynthesis, triacylglycerol synthesis, and TAG packaging presented increased activity in the later stages of tuber development. Notably, high-oil tubers showed higher levels of expression of genes involved in oil synthesis than medium-oil tubers, while low-oil tubers showed almost no expression of these genes.

Furthermore, a lack of an important fatty acid (FA) biosynthesis rate-limiting enzyme encoding gene was found in C. rotundus transcripts, which may have implications for its oil accumulation capacity.

“Our study identified potential genes and networks associated with tuber oil accumulation in C. esculentus, highlighting the role of specific genes, transcription factors, and ethylene signaling in this process,” said TANG Mingyong of XTBG.

Contact

TANG Mingyong Ph.D Principal Investigator

Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, Yunnan, China    

E-mail: tangmingyong@xtbg.ac.cn     

First published: 16 August 2024