Comparative Analysis the Complete Chloroplast Genomes of Nine Musa Species: Genomic Features, Comparative Analysis, and Phylogenetic Implications.

Zimeng Chen,Shuo Wang,Chuxuan Ji,Chao Shi,Haohong Cai,Xiaomeng Wu,Weicai Song

doi:10.3389/fpls.2022.832884

Abstract

Musa (family Musaceae) is monocotyledonous plants in order Zingiberales, which grows in tropical and subtropical regions. It is one of the most important tropical fruit trees in the world. Herein, we used next-generation sequencing technology to assemble and perform in-depth analysis of the chloroplast genome of nine new Musa plants for the first time, including genome structure, GC content, repeat structure, codon usage, nucleotide diversity and etc. The entire length of the Musa chloroplast genome ranged from 167,975 to 172,653 bp, including 113 distinct genes comprising 79 protein-coding genes, 30 transfer RNA (tRNA) genes and four ribosomal RNA (rRNA) genes. In comparative analysis, we found that the contraction and expansion of the inverted repeat (IR) regions resulted in the doubling of the rps19 gene. The several non-coding sites (psbI–atpA, atpH–atpI, rpoB–petN, psbM–psbD, ndhf–rpl32, and ndhG–ndhI) and three genes (ycf1, ycf2, and accD) showed significant variation, indicating that they have the potential of molecular markers. Phylogenetic analysis based on the complete chloroplast genome and coding sequences of 77 protein-coding genes confirmed that Musa can be mainly divided into two groups. These genomic sequences provide molecular foundation for the development and utilization of Musa plants resources. This result may contribute to the understanding of the evolution pattern, phylogenetic relationships as well as classification of Musa plants.

Highlights

Musaceae is a small family of Zingiberales in monocotyledonous plants, mostly distributed in tropical regions in Australia, Africa, and Asia
The GC content of small single copy (SSC) regions was similar in nine species, ranging from 30.1% in M. rubinea to 31.2% in Musa laterita. 33,864–35,522 bp was the length range of the inverted repeat (IR) region of nine Musa species, which contains 39.5–40.0% GC content
Our analysis shows that the proportion of Long repeats (LR) of M. laterita, M. mannii, M. nagensium, M. rubinea, and M. yunnanensis in the IR regions were greater than that of the other four species, which may play a role in the genetic diversity and evolution of different Musa branches

Summary

Introduction

Musaceae is a small family of Zingiberales in monocotyledonous plants, mostly distributed in tropical regions in Australia, Africa, and Asia. While most species of the family, which occur mainly in Southeast Asia, are classified into the Musa group (Häkkinen and Väre, 2008). Musa grow in tropical and subtropical regions and is one of the most important tropical fruit trees in the world. Wild Musa species are reclassified into two groups, Musa L. sect. Banana fiber has become one of the high potential biological resources in new material field due to it’ s characteristics such as sustainability, low cost and environmental friendliness (Pappu et al, 2015; Vishnuvarthanan et al, 2019). The leaf fibers of abaca (Musa textilis) are ideal raw materials for manufacturing specialty paper (del Río and Gutiérrez, 2006). Banana starch plays an important role in the food, pharmaceutical, and cosmetic industries (RamírezHernández et al, 2017; Arias et al, 2021; Taweechat et al, 2021; Thanyapanich et al, 2021)

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Conclusion