jasmonatedependent

Jasmonate-dependent refers to biological processes in plants that are regulated by jasmonic acid (JA) and its derivatives, collectively known as jasmonates. Jasmonates are a class of plant hormones that play a crucial role in various developmental and defense responses. When a plant encounters a stressor, such as herbivore attack or pathogen infection, the levels of jasmonates typically increase. This elevation in jasmonate signaling then triggers a cascade of downstream events that help the plant cope with the stress.

The jasmonate-dependent pathway is particularly important for plant defense. Upon perception of damage or threat, JA is synthesized and then conjugated to amino acids to form jasmonyl-isoleucine (JA-Ile), which is considered the active form of the hormone. JA-Ile binds to receptor complexes, often consisting of COI1 (coronatine-insensitive 1) and JAZ (Jasmonate Zim-domain) proteins. This binding leads to the degradation of JAZ repressors, thereby releasing transcription factors like MYC2. These activated transcription factors then bind to specific DNA sequences, upregulating the expression of defense-related genes. These genes can encode for a variety of protective compounds, including proteinase inhibitors, secondary metabolites with toxic or repellent properties, and enzymes involved in cell wall strengthening.

Beyond defense, jasmonate-dependent pathways are also involved in plant growth and development. They influence processes such as root growth, senescence (programmed aging of plant tissues), and seed germination. The specific responses mediated by jasmonates are often context-dependent, meaning the plant's developmental stage and the environmental conditions can influence the outcome of jasmonate signaling. Understanding jasmonate-dependent mechanisms is vital for agricultural applications, such as enhancing crop resistance to pests and diseases.