Mikania micrantha genome provides insights into the molecular mechanism of rapid growth

Bo Liu,Qilei Zhang,Fanghao Wan,Minling Cai,Haihong Wang,Zhenzhen Wang,Qiaojing Ou,Xi Qiao,Yaping Zheng,Shubin Li,Jian Yan,Hengchao Wang,Hongxian Yu ,Jiao Guo ,Lei Yin ,Fan Jiang,Yingxue Ren ,Ping Li,Wanqiang Qian,Mengxin Zhao,Weihua Li,Qin Lu ,Hangwei Liu,Yu X ,Yan Zhang,Longsheng Xing,Zheng Jian ,Cong Huang,Conghui Liu,Hui Dong,Zhaoyang Jiang,Chang-Lian Peng ,Feng Sun,Wei Fan,Sen Wang

doi:10.1038/s41467-019-13926-4

Abstract

Mikania micrantha is one of the top 100 worst invasive species that can cause serious damage to natural ecosystems and substantial economic losses. Here, we present its 1.79 Gb chromosome-scale reference genome. Half of the genome is composed of long terminal repeat retrotransposons, 80% of which have been derived from a significant expansion in the past one million years. We identify a whole genome duplication event and recent segmental duplications, which may be responsible for its rapid environmental adaptation. Additionally, we show that M. micrantha achieves higher photosynthetic capacity by CO2 absorption at night to supplement the carbon fixation during the day, as well as enhanced stem photosynthesis efficiency. Furthermore, the metabolites of M. micrantha can increase the availability of nitrogen by enriching the microbes that participate in nitrogen cycling pathways. These findings collectively provide insights into the rapid growth and invasive adaptation.

Highlights

Mikania micrantha is one of the top 100 worst invasive species that can cause serious damage to natural ecosystems and substantial economic losses
Given the common name “mile-a-minute”, one of the most distinctive features of M. micrantha is its fast growth, which strongly relies on its photosynthesis ability[1]
We found that the variation pattern of malic acid content, citric acid content, stomatal conductance and key genes expression, such as PEPC, carbonic anhydrase (CA), NADP-malic enzyme (ME), are consistent with classic Crassulacean acid metabolism (CAM) plants

Summary

Introduction

Mikania micrantha is one of the top 100 worst invasive species that can cause serious damage to natural ecosystems and substantial economic losses. The metabolites of M. micrantha can increase the availability of nitrogen by enriching the microbes that participate in nitrogen cycling pathways These findings collectively provide insights into the rapid growth and invasive adaptation. M. micrantha possesses a variety of biological characteristics associated with successful invasive plant species. It germinates early in the growing season; grows extremely fast (with a maximum mean growth rate of 20 cm day−1)[12]; roots from each vine node; has a smothering habit; produces very large numbers of widely dispersed seeds (170,000 m−2)[13], which are very small (8.92 × 10−5 g 1000 grains−1)[14,15]; and has an ability to survive harsh conditions[15]. Some studies have examined the biological characteristics of M. micrantha, genomic and molecular data are scarce, which limits in-depth studies of this invasive species

Methods

Results

Conclusion