Establishment of the model system between phytochemicals and gene expression profiles in Macrosclereid cells of Medicago truncatula

Abstract

Macrosclereid cells, which are a layer in the seed coat of Medicago truncatula, accumulate large amounts of phytochemicals during their development. But little is known about the complex and dynamic changes during macrosclereid cell development. To characterize the phytochemicals and the related gene expression during the development of M. truncatula macrosclereid cells, a high performance liquid chromatography-mass spectrometry (HPLC-MS) assay and microarray study were conducted on transcriptome changes from macrosclereid cell during seed development. A total of 16 flavonoids by HPLC-MS and 4861 genes exhibited significant differences at transcript levels by microarray analysis were identified for macrosclerid cells at six different time points during seed development. 815 abiotic and biotic stress genes, 223 transcriptional factors (TFs), and 155 annotated transporter proteins exhibited differential expression during the development of macrosclereid cells. A total of 102 genes were identified as involved in flavonoid biosynthesis, phenypropanoid biosynthesis, and flavone and flavonol biosynthesis. We performed a weighted gene co-regulatory network (WGCNA) to analyze the gene-flavonoid association and rebuilt the gene regulatory network during macrosclereid cell development. Our studies revealed that macrosclereid cells are, beside as the first barrier of defense against diseases, an excellent model system to investigate the regulatory network that governs flavonoid biosynthesis.

Anatomy and Histochemistry of Seed Coat Development of Wild (Pisum sativum subsp. elatius (M. Bieb.) Asch. et Graebn. and Domesticated Pea (Pisum sativum subsp. sativum L.)

“…Most commonly, studies have pointed out that the macrosclereid cell layer controls the water entry [ 13 ] and M. truncatula mutants with a defective outer cell layer differentiation, and in particular cuticle deposition, have supported this [ 49 ]. Cells of the macroslereid layer are rich in secondary metabolites and correlations between pigmentation and SC permeability were shown [ 13 , 19 , 41 ]. Analysis of the chemical composition of pea SC showed that polysaccharides, such as hemicellulose, cellulose, and especially pectins, comprise the largest proportion and their deposition is developmentally regulated [ 50 ].…”

“…Legume seed development has been studied in Medicago truncatula Gaertn. [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ] and cultivated pea [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. Early in development, legume SC is a transient storage organ, which accumulates starch and proteins before storage activity starts in the embryo.…”

Physical Dormancy Release in Medicago truncatula Seeds Is Related to Environmental Variations

“…To link identified QTNs with putative causal gene by considering the linkage disequilibrium (LD), we selected all SNPs correlated (r 2 > 0.7) with the top identified QTNs within a 15kb genomic range, corresponding to the average LD block size present in the Medicago Hapmap population [100,102], and we listed gene IDs closely related to these SNPs. Seed expression pattern of the candidate genes was assessed using published Medicago seeds or seed coat expression studies [103,104] and web-based expression atlas [105]…”

Identification of Regulatory SNPs Associated with Vicine and Convicine Content of Vicia faba Based on Genotyping by Sequencing Data Using Deep Learning

“…Its members are involved in the regulation of development, metabolism, the circadian rhythm, and responses to biotic and abiotic stresses in plants [74,79,80]. In Medicago truncatula multiple MYB TFs including MYB4 and MYB61 are involved in flavonoid biosynthesis during macrosclereid cell development [81]. MYB4 in particular regulates abiotic stress responses towards UV-B light and cadmium toxicity in Arabidopsis thaliana [82,83] and cold in Oryza sativa [84].…”