Abstract Salicylic acid (SA) plays a pivotal role in plant response to biotic and abiotic stress. Several core SA signaling regulators and key proteins in SA biosynthesis have been well charactered. However, much remains unknown about the origin, evolution, and early diversification of core elements in plant SA signaling and biosynthesis. Here, we identified ten core protein families in SA signaling and biosynthesis across green plant lineages. We found that key SA signaling receptors, the nonexpresser of pathogenesis-related proteins (NPRs), originated in the most recent common ancestor (MRCA) of land plants and formed divergent groups in the ancestor of seed plants.
Summary Phosphorus (P) is an essential element for plant growth and development. Vacuoles play a fundamental role in the storage and remobilization of P in plants, while our understanding of the evolutionary mechanisms of creating and reusing P stores are limited. Besides, we also know very little about the coordination of intercellular P translocation, neither the inorganic phosphate (Pi) signaling nor the Pi transport patterns. Here we summarize recent advances in understanding the core elements involved in cellular and/or subcellular P homeostasis and signaling in unicellular green algae and multicellular land plants.
Summary Phosphorus is an essential nutrient for plants. It is stored as inorganic phosphate (Pi) in vacuoles of land plants but as inorganic polyphosphate (polyP) in chlorophyte algae. Although it has been known that the SPX-MFS and VPE proteins are respectively responsible for Pi influx and efflux across the tonoplast in land plants, the mechanisms underlying polyP homeostasis and the transition of phosphorus storage forms during the evolution of green plants remain unclear.