The genome of Cleistogenes songorica provides a blueprint for functional dissection of dimorphic flower differentiation and drought adaptability

Autor: Jiyu Zhang, Jie Li, Pan Xu, Yanyan Lv, Ruijuan Liu, Gisele Kanzana, Qi Yan, German Spangenberg, Yanrong Wang, Ulrik P. John, Zhengshe Zhang, Yufei Zhang, Mingshu Cao, Xifang Zong, Tiantian Ma, Yufeng Zhao, Zhibiao Nan, Fan Wu
Rok vydání: 2020
Předmět:
Zdroj: Plant Biotechnology Journal
ISSN: 1467-7652
1467-7644
DOI: 10.1111/pbi.13483
Popis: Cleistogenes songorica (2n = 4x = 40) is a desert grass with a unique dimorphic flowering mechanism and an ability to survive extreme drought. Little is known about the genetics underlying drought tolerance and its reproductive adaptability. Here, we sequenced and assembled a high-quality chromosome-level C. songorica genome (contig N50 = 21.28 Mb). Complete assemblies of all telomeres, and of ten chromosomes were derived. C. songorica underwent a recent tetraploidization (similar to 19 million years ago) and four major chromosomal rearrangements. Expanded genes were significantly enriched in fatty acid elongation, phenylpropanoid biosynthesis, starch and sucrose metabolism, and circadian rhythm pathways. By comparative transcriptomic analysis we found that conserved drought tolerance related genes were expanded. Transcription of CsMYB genes was associated with differential development of chasmogamous and cleistogamous flowers, as well as drought tolerance. Furthermore, we found that regulation modules encompassing miRNA, transcription factors and target genes are involved in dimorphic flower development, validated by overexpression of CsAP2_9 and its targeted miR172 in rice. Our findings enable further understanding of the mechanisms of drought tolerance and flowering in C. songorica, and provide new insights into the adaptability of native grass species in evolution, along with potential resources for trait improvement in agronomically important species.
Databáze: OpenAIRE
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