Genome-Wide Analysis of Coding and Long Non-Coding RNAs Involved in Cuticular Wax Biosynthesis in Cabbage (Brassica oleracea L. var. capitata).

Xiaowei Zhu,Jinxiu Chen,Yunying Ren,Tianyue Bo,Xiang Tai

doi:10.3390/ijms20112820

Xiaowei Zhu, Jinxiu Chen + Show 3 more

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https://doi.org/10.3390/ijms20112820

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Abstract

Cuticular wax is a mixture of very long chain fatty acids (VLCFAs) and their derivatives, which determines vital roles for plant growth. In cabbage, the cuticular wax content of leaf blades is an important trait influencing morphological features of the head. Understanding the molecular basis of cuticular wax biosynthesis can help breeders develop high quality cabbage varieties. Here, we characterize a cabbage non-wax glossy (nwgl) plant, which exhibits glossy green phenotype. Cryo-scanning electron microscope analysis showed abnormal wax crystals on the leaf surfaces of nwgl plants. Cuticular wax composition analyzed by GC-MS displayed severely decreased in total wax loads, and individual wax components in nwgl leaves. We delimited the NWGL locus into a 99-kb interval between the at004 marker and the end of chromosome C08 through fine mapping. By high-throughput RNA sequencing, we identified 1247 differentially expressed genes (DEGs) and 148 differentially expressed lncRNAs in nwgl leaves relative to the wild-type. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the DEGs and cis-regulated target genes for differentially expressed lncRNAs were significantly enriched in wax and lipid biosynthetic or metabolic processes. Our results provide the novel foundation to explore the complex molecular basis of cuticular wax biosynthesis.

Highlights

The aerial surface of land plants is covered with a hydrophobic cuticle layer, which is composed of two major lipid components, the cutin polyester and the non-polymerized cuticular waxes
The phenotype and characterization of the nwgl plants reported here showed that NWGL is a factor for cuticular wax biosynthesis in cabbage
The nwgl leaf blades exhibited decreased contents of very long chain fatty acids (VLCFAs), alkanes and primary alcohols, and the abortion of secondary alcohol and ketone (Table 1), indicating that NWGL acted as an major regulator for VLCFA elongation and the two distinct pathways, the alkane-forming and alcohol-forming pathways

Summary

Introduction

The aerial surface of land plants is covered with a hydrophobic cuticle layer, which is composed of two major lipid components, the cutin polyester and the non-polymerized cuticular waxes. Cuticular waxes are predominantly composed of very long chain fatty acids (VLCFAs) and their derivatives, including aldehydes, alcohols, alkanes, ketones, and esters [1,2]. Cuticular wax protects plants against numerous biotic and abiotic stresses, such as pathogen infection and non-stomatal water loss [5,6]. It plays important roles in normal plant developmental processes, including the pollen–pistil interaction [7]. Identifying plants with cuticular wax deficiency and elucidating the regulatory mechanisms controlling cuticular wax biosynthesis will be beneficial for improving agricultural crops

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