De novo assembly, transcriptome characterization, lignin accumulation and anatomic characteristics: novel insights into lignin biosynthesis during celery leaf development

Abstract

Celery of the family Apiaceae is a biennial herb that is cultivated and consumed worldwide. Lignin is essential for cell wall structural integrity, stem strength, water transport, mechanical support, and plant pathogen defense. This study discussed the mechanism of lignin formation at different stages of celery development. The transcriptome profile, lignin distribution, anatomical characteristics, and expression profile of leaves at three stages were analyzed. Regulating lignin synthesis in celery growth development has a significant economic value. Celery leaves at three stages were collected, and Illumina paired-end sequencing technology was used to analyze large-scale transcriptome sequences. From Stage 1 to 3, the collenchyma and vascular bundles in the petioles and leaf blades thickened and expanded, whereas the phloem and the xylem extensively developed. Spongy and palisade mesophyll tissues further developed and were tightly arranged. Lignin accumulation increased in the petioles and the mesophyll (palisade and spongy), and the xylem showed strong lignification. Lignin accumulation in different tissues and at different stages of celery development coincides with the anatomic characteristics and transcript levels of genes involved in lignin biosynthesis. Identifying the genes that encode lignin biosynthesis-related enzymes accompanied by lignin distribution may help elucidate the regulatory mechanisms of lignin biosynthesis in celery.

The genome sequence of celery (Apium graveolens L.), an important leaf vegetable crop rich in apigenin in the Apiaceae family

“…Two FNSI genes were detected in celery but not in Arabidopsis, rice, or tomato. Based on celery RNA-seq data from three developmental stages 63,64 , the expression changes in apigenin-related genes were analyzed, and the results were presented in a heatmap. Most of the apigenin biosynthesis-related genes showed the highest expression levels at early stages, and their expression trends decreased with celery growth and development (Fig.…”

“…In the celery genome, the TPS-b and TPS-a subfamilies contained 17 and 13 members, and only six and two proteins belonged to the TPS-e/f and TPS-c subfamilies, respectively, whereas no proteins clustered within the TPS-g subfamily in celery. Based on previous transcriptome data from celery 63,64 , we further analyzed the expression abundance of TPS genes in three developmental stages. As illustrated in Fig.…”

De novo transcriptome sequencing and gene expression profiling of spinach (Spinacia oleracea L.) leaves under heat stress

“…Next-generation sequencing (NGS) technologies, such as Illumina/Solexa (San Diego, CA, USA), the SOLiD platform from Applied Biosystems, and Roche 454 sequencing, have revolutionized genomics because they allow faster and less expensive sequencing 5 . NGS-based RNA-Seq methods, which are used for transcriptome analysis, even allow simultaneous acquisition of sequences 6 . These fast sequencing methods are used to characterize genes, detect gene expression pattern and level, recognize and quantify rare transcripts without prior information of the particular gene or reference genome, and generate information on alternative splicing and sequence variations in identified genes 6 7 .…”

The Apiaceae: Ethnomedicinal family as source for industrial uses

“…However, a significant diversity of chemical composition is detected depending on the seed varieties, genetic sources and en vironmental conditions (Table 2). Apiaceae seeds are also a rich source of water soluble glycosides of monoterpenoid, alkyl and aromatic compounds as well as, cellulose, lignin, wax esters, pectins, phospho lipids, flavonoids, hydroxycoumarins, carotenoids, terpenoids and other types of compounds including sugars, lactones and quinones (Jia et al, 2015).…”