Rye is a valuable food and forage crop, an important genetic resource for wheat and triticale improvement and an indispensable material for efficient comparative genomic studies in grasses. Here, we sequenced the genome of Weining rye, an elite Chinese rye variety. The assembled contigs (7.74 Gb) accounted for 98.47% of the estimated genome size (7.86 Gb), with 93.67% of the contigs (7.25 Gb) assigned to seven chromosomes. Repetitive elements constituted 90.31% of the assembled genome. Compared to previously sequenced Triticeae genomes, Daniela, Sumaya and Sumana retrotransposons showed strong expansion in rye. Further analyses of the Weining assembly shed new light on genome-wide gene duplications and their impact on starch biosynthesis genes, physical organization of complex prolamin loci, gene expression features underlying early heading trait and putative domestication-associated chromosomal regions and loci in rye. This genome sequence promises to accelerate genomic and breeding studies in rye and related cereal crops.

The Arabidopsis MYB107 transcription factor regulates the expression of suberin biosynthetic genes in developing seeds, thereby controlling the synthesis and as

Calcium pumps ACA10 and ACA8 and their interacting protein BON1 regulate calcium signatures and impact stomatal movement and plant immunity in Arabidopsis.

In contrast to large‐effect qualitative disease resistance, quantitative disease resistance (QDR) exhibits partial and generally durable resistance and has been extensively utilized in crop breeding. The molecular mechanisms underlying QDR remain largely unknown but considerable progress has been made in this area in recent years. In this review, we summarize the genes that have been associated with plant QDR and their biological functions. Many QDR genes belong to the canonical resistance gene categories with predicted functions in pathogen perception, signal transduction, phytohormone homeostasis, metabolite transport and biosynthesis, and epigenetic regulation. However, other “atypical” QDR genes are predicted to be involved in processes that are not commonly associated with disease resistance, such as vesicle trafficking, molecular chaperones, and others. This diversity of function for QDR genes contrasts with qualitative resistance, which is often based on the actions of nucleotide‐binding leucine‐rich repeat (NLR) resistance proteins. An understanding of the diversity of QDR mechanisms and of which mechanisms are effective against which classes of pathogens will enable the more effective deployment of QDR to produce more durably resistant, resilient crops.

Angiosperms have evolved the metabolic capacity to synthesize p-hydroxyphenyl, guaiacyl (G), and syringyl (S) lignin subunits in their cell walls to better adapt to the harsh terrestrial environment. The structural characteristics of lignin subunits are essentially determined by three cytochrome P450-catalzyed reactions. NADPH-dependent cytochrome P450 oxidoreductase (CPR) is commonly regarded as the electron carrier for P450-catalyzed reactions during monolignol biosynthesis. Here, we show that cytochrome b₅ isoform D (CB5D) is an indispensable electron shuttle protein specific for S-lignin biosynthesis. Arabidopsis (Arabidopsis thaliana) CB5D localizes to the endoplasmic reticulum membrane and physically associates with monolignol P450 enzymes. Disrupting CB5D in Arabidopsis resulted in a >60% reduction in S-lignin subunit levels but no impairment in G-lignin formation compared with the wild type, which sharply contrasts with the impaired G- and S-lignin synthesis observed after disrupting ATR2, encoding Arabidopsis CPR. The defective S-lignin synthesis in cb5d mutants was rescued by the expression of the gene encoding CB5D but not with mutant CB5D devoid of its electron shuttle properties. Disrupting ATR2 suppressed the catalytic activity of both cinnamic acid 4-hydroxylase and ferulate 5-hydroxylase (F5H), but eliminating CB5D specifically depleted the latter’s activity. Therefore, CB5D functions as an obligate electron shuttle intermediate that specifically augments F5H-catalyzed reactions, thereby controlling S-lignin biosynthesis.