Summary: Cannabis (Cannabis sativa L.) is one of the oldest cultivated plants purported to have unique medicinal properties. However, scientific research of cannabis has been restricted by the Single Convention on Narcotic Drugs of 1961, an international treaty that prohibits the production and supply of narcotic drugs except under license. Legislation governing cannabis cultivation for research, medicinal and even recreational purposes has been relaxed recently in certain jurisdictions. As a result, there is now potential to accelerate cultivar development of this multi‐use and potentially medically useful plant species by application of modern genomics technologies. Whilst genomics has been pivotal to our understanding of the basic biology and molecular mechanisms controlling key traits in several crop species, much work is needed for cannabis. In this review we provide a comprehensive summary of key cannabis genomics resources and their applications. We also discuss prospective applications of existing and emerging genomics technologies for accelerating the genetic improvement of cannabis.

Secondary cell walls (SCWs) are formed in some specific types of plant cells, providing plants with mechanical strength. During plant growth and development, formation of secondary cell walls is regulated by various developmental and environmental signals. The underlying molecular mechanisms are poorly understood. In this study, we analyzed the blue light receptor cryptochrome1 (cry1) mutant of Arabidopsis thaliana for its SCW phenotypes. During inflorescence stem growth, SCW thickening in the vasculature was significantly affected by blue light. cry1 plants displayed a decline of SCW thickening in fiber cells, while CRY1 overexpression led to enhanced SCW formation. Transcriptome analysis indicated that the reduced SCW thickening was associated with repression of the NST1-directed transcription regulatory networks. Further analyses revealed that the expression of MYC2/MYC4 that is induced by blue light activates the transcriptional network underlying SCW thickening. The activation is caused by direct binding of MYC2/MYC4 to the NST1 promoter. This study demonstrates that SCW thickening in fiber cells is regulated by a blue light signal that is mediated through MYC2/MYC4 activation of NST1-directed SCW formation in Arabidopsis.

Heteroxylans are abundant components of plant cell walls and provide important raw materials for the food, pharmaceutical, and biofuel industries. A number of studies in Arabidopsis (Arabidopsis thaliana) have suggested that the IRREGULAR XYLEM9 (IRX9), IRX10, and IRX14 proteins, as well as their homologs, are involved in xylan synthesis via a Golgi-localized complex termed the xylan synthase complex (XSC). However, both the biochemical and cell biological research lags the genetic and molecular evidence. In this study, we characterized garden asparagus (Asparagus officinalis) stem xylan biosynthesis genes (AoIRX9, AoIRX9L, AoIRX10, AoIRX14A, and AoIRX14B) by heterologous expression in Nicotiana benthamiana. We reconstituted and partially purified an active XSC and showed that three proteins, AoIRX9, AoIRX10, and AoIRX14A, are necessary for xylan xylosyltranferase activity in planta. To better understand the XSC structure and its composition, we carried out coimmunoprecipitation and bimolecular fluorescence complementation analysis to show the molecular interactions between these three IRX proteins. Using a site-directed mutagenesis approach, we showed that the DxD motifs of AoIRX10 and AoIRX14A are crucial for the catalytic activity. These data provide, to our knowledge, the first lines of biochemical and cell biological evidence that AoIRX9, AoIRX10, and AoIRX14A are core components of a Golgi-localized XSC, each with distinct roles for effective heteroxylan biosynthesis.

KNS4/UPEX1 is involved in the synthesis of type II AG of AGPs/pectins that are essential components of pollen grain walls providing the scaffold for exine const

Evaluation of hydroxyproline-rich glycoproteins identified in 1KP transcriptomic data sets to gain insight into their evolutionary history from chlorophyte alga

An innovative bioinformatics pipeline to identify and classify a plant-specific superfamily of cell wall hydroxyproline-rich glycoproteins provides evolutionary