Expression Analysis of Cell Wall-Related Genes in Cannabis sativa: The “Ins and Outs” of Hemp Stem Tissue Development

Abstract

Textile hemp (Cannabis sativa L.) is a multipurpose crop producing biomass with uses in e.g., the textile, biocomposite, and construction sectors. It was previously shown that the hypocotyl of hemp is useful to study the kinetics of secondary tissue development, where primary and secondary growths are temporally uncoupled. We here sought to demonstrate that the stem of adult hemp plants is an additional suitable model to study the heterogeneous lignification of the tissues and the mechanisms underlying secondary cell wall formation in bast fibres. A targeted quantitative PCR analysis carried out on a set of twenty genes involved in cell wall biosynthesis clearly showed differences in expression in the core and cortical tissues along four stem regions spanning from elongation to cell wall thickening. Genes involved in phenylpropanoid biosynthesis and secondary cell wall cellulose synthases were expressed at higher levels in core tissues at the bottom, while specific genes, notably a class III peroxidase and a gene partaking in lignan biosynthesis, were highly expressed in the cortex of elongating internodes. The two systems, the hypocotyl and the adult stem of textile hemp, are equally valid and complementary to address questions related to lignification and secondary cell wall deposition.

Distribution of cell-wall polysaccharides and proteins during growth of the hemp hypocotyl

“…RT-qPCR analyses were performed in 384-well plates on a ViiA7 Real-Time PCR System (Applied Biosystems) with the Takyon SYBR Green low ROX (Eurogentec). The primers were designed and validated as described (Behr et al 2018a) and the primer list can be found in the same manuscript. The sequences used for primer design are given in Supplementary Document S1.…”

High-resolution genetic dissection of the major QTL for tipburn resistance in lettuce,Lactuca sativa

“…Emperor of Lsat_1_v5_gn_5_140040 has on tipburn incidence; however, the cell wall could play a role in tipburn incidence by acting as a sink for Ca 2+ or influencing cellular integrity. Lsat_1_v5_gn_5_135361 encodes for β-galactosidase 2 (BGAL2), which has been shown to be important in secondary cell wall formation in flax ( Linum usitatissinum ) and hemp ( Cannabis sativa ; Roach et al 2011 and Behr et al 2018 ). However, Moneo-Sánchez et al (2018) studied knockout mutants of several BGAL genes and found no significant phenotypic changes, which lead them to conclude that other β-galactosidases from the same subfamily can compensate for the loss of function of these proteins.…”