Salicylic Acid: Biosynthesis and Signaling.

Salicylic acid (SA) is an essential plant defense hormone that promotes immunity against biotrophic and semibiotrophic pathogens. It plays crucial roles in basal defense and the amplification of local immune responses, as well as the establishment of systemic acquired resistance. During the past three decades, immense progress has been made in understanding the biosynthesis, homeostasis, perception, and functions of SA.

Brassinosteroids Antagonize Jasmonate-Activated Plant Defense Responses through BRI1-EMS-SUPPRESSOR1 (BES1).

Brassinosteroids (BRs) and jasmonates (JAs) regulate plant growth, development, and defense responses, but how these phytohormones mediate the growth-defense tradeoff is unclear. Here, we identified the Arabidopsis () () mutant, which exhibits enhanced expression of defensin genes () and The mutant showed increased resistance to herbivory by beet armyworms () and infection by botrytis (). encodes ROTUNDIFOLIA3, a cytochrome P450 protein essential for BR biosynthesis.

Plants Engineered To Produce Astaxanthin Show Enhanced Oxidative Stress Tolerance and Bacterial Pathogen Resistance.

Carotenoids play key roles in photosynthesis and photoprotection. Few multicellular plants produce the ketocarotenoid astaxanthin, a strong antioxidant; however, lines overexpressing the β-carotene ketolase () accumulated high amounts of astaxanthin in the leaves. In this study, we investigated the changed regulation of key metabolic pathways and the tolerance of the engineered plants to biotic and abiotic stresses resulting from the heterologous expression of .

Opposite Roles of Salicylic Acid Receptors NPR1 and NPR3/NPR4 in Transcriptional Regulation of Plant Immunity.

Salicylic acid (SA) is a plant defense hormone required for immunity. Arabidopsis NPR1 and NPR3/NPR4 were previously shown to bind SA and all three proteins were proposed as SA receptors. NPR1 functions as a transcriptional co-activator, whereas NPR3/NPR4 were suggested to function as E3 ligases that promote NPR1 degradation.

Perception of Salicylic Acid in .

Salicylic acid (SA) is a key signaling molecule in plant immunity. Two types of SA receptors, NPR1 and NPR3/NPR4, were reported to be involved in the perception of SA in Arabidopsis. SA is also synthesized in the non-vascular moss following pathogen infection.

Convergent and Divergent Signaling in PAMP-Triggered Immunity and Effector-Triggered Immunity.

Plants use diverse immune receptors to sense pathogen attacks. Recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors localized on the plasma membrane leads to PAMP-triggered immunity (PTI). Detection of pathogen effectors by intracellular or plasma membrane-localized immune receptors results in effector-triggered immunity (ETI).