Figure 3

Genes involved in ABA homeostasis and perception are expanded in quinoa. (A) Diagram of the ABA biosynthetic pathway. The arrows indicate the direction of biochemical reactions. Enzymes that catalyze the reaction are indicated next to the arrow: ZEP, zeaxanthin epoxidase; VDE, violaxanthin de-epoxidase; ABA4, abscisic acid-deficient 4; NSY, neoxanthin synthase; NXD1, neoxanthin-deficient 1; NCED, 9-cis-epoxycarotenoid dioxygenases; SDR, short-chain dehydrogenases/reductases; AAO, aldehyde oxidase. (B) Copy number of genes involved in ABA biosynthesis, transport and perception in quinoa and seven other plant species. Red numbers indicate gene copy numbers that are higher in quinoa. The phylogenetic relationship of these species is indicated at the top of the graph, inferred from single-copy orthologous gene sets. Genes involved in ABA biosynthesis, transport and perception are shaded in orange, yellow and pink color, respectively. (C) Heatmap showing the transcript level of ABA-responsive genes across different quinoa tissues. Functional characterization is based on the GO (gene ontology) annotation. In total, 108 genes in quinoa genome were assigned as a “response to ABA”, and 92 of those (85%) are expressed in at least one of the seven types of tissues. Tissues are indicated in short names: Sl, seedlings; L − B, leaf without bladders; L + B, leaf with bladders; B, bladder cells; St, stem; In, inflorescence; YS, young seeds. Species are indicated by two-letter names: Ah, Amaranthus hypochondriacus; At, Arabidopsis thaliana; Bv, sugar beet (Beta vulgaris); Cq, quinoa (Chenopodium quinoa); Sl, tomato (Solanum lycopersicum); So, spinach (Spinacia oleracea L.); St, potato (Solanum tuberosum); Vv, grape (Vitis vinifera).