Jasmonate

Plants have special tools to stay safe.

They use tiny signals to grow and change. These signals help when bugs try to eat them. The plant makes a special part to fight back. This part can even stop bugs from eating leaves.

Some plants use these signals to catch food. The Venus flytrap uses them to close its trap. Plants also send smells through the air. This tells nearby plants to get ready for danger. It is a smart way to stay healthy.

Plants use tiny signals to grow and stay healthy. One important signal is called jasmonate (JA). These are plant hormones, which are natural chemicals that control how a plant works.

Jasmonates help plants grow and make flowers. They also help plants fight back when bugs try to eat them.

When a bug bites a leaf, the plant makes more jasmonate. This helps the plant start a defense. For example, tomato plants make chemicals that stop insects from digesting their leaves. Some jasmonates can even turn into smells. These smells travel through the air to nearby plants. This tells them to get ready for danger.

Some plants use these signals in new ways. The Venus flytrap uses jasmonate to close its traps. It also uses it to help digest food.

Inside the plant, a protein called JAZ acts like an on-off switch. When jasmonate is present, it removes the JAZ protein. This lets the plant turn on the genes it needs to stay safe.

Plants use special signals to manage their lives. These signals are called jasmonates, or JA for short. They are lipid-based plant hormones. This means they are natural chemicals made from fats. Jasmonates help plants in many ways. They control how a plant grows and how it makes food through photosynthesis. They also help with making flowers and seeds. Most importantly, they help plants defend themselves. They protect plants from being eaten by bugs. They also help plants handle hard times, like bad weather.

How do these signals work inside a plant? It starts with a fatty acid called linolenic acid. This happens inside a part of the cell called a chloroplast. The plant turns that acid into a new substance called OPDA. Next, the process moves to a part of the cell called a peroxisome. There, the plant goes through several steps to turn OPDA into jasmonic acid. The plant can then change this acid into different forms. One form is called methyl jasmonate, or MeJA. This form is a volatile compound. This means it can turn into a gas and travel through the air.

Scientists have studied these signals for a long time. In 1962, researchers found methyl jasmonate in jasmine oil. They got this oil from a plant named Jasminum grandiflorum. This discovery helped them learn the structure of jasmonates. Later, in 1971, other scientists isolated jasmonic acid itself. They found it in a fungus called Lasiodiplodia theobromae. Since then, many people have studied how these chemicals are made. They have looked at how plants use them to survive.

Jasmonates do many different jobs. When a bug bites a leaf, the plant quickly makes more JA. In tomato plants, this creates molecules that stop insects from digesting the leaves. This signal can also travel to nearby plants. The smell of MeJA tells neighbors to get ready for danger. Some plants even use these signals to eat! The Venus flytrap uses jasmonate to close its traps. It also uses it to release enzymes to digest its food.

Inside the plant cells, there is a clever on-off switch. This switch is a protein called JAZ. When there is no jasmonate, JAZ proteins stay attached to other parts of the cell. They stop certain genes from working. This keeps the plant's defenses turned off to save energy. But when jasmonate arrives, it changes everything. The jasmonate binds to a protein called COI1. This causes the JAZ proteins to be broken down and removed. Once JAZ is gone, the plant can turn on the genes it needs to fight back.

Jasmonates (JA) are a group of lipid-based plant hormones. These chemicals act as vital signaling molecules that regulate many biological processes. They manage everything from growth and photosynthesis to reproductive development. Most importantly, jasmonates are critical for plant defense. They help plants respond to herbivory, which is when animals eat them. They also help plants survive abiotic challenges, like poor environmental conditions. Some jasmonates can even travel through the air as volatile organic compounds (VOCs). This allows plants to communicate with their neighbors about approaching dangers.

The production of jasmonates, known as biosynthesis, follows a specific chemical path. It begins in the chloroplast membranes of the plant cell. Here, the plant converts a fatty acid called linolenic acid into 12-oxo-phytodienoic acid, or OPDA. This is the only step that occurs in the chloroplast. The process then moves to a different part of the cell called the peroxisome. In the peroxisome, the OPDA undergoes a reduction and three rounds of oxidation. This sequence transforms the substance into (+)-7-iso-JA, which is jasmonic acid.

Once jasmonic acid is made, the plant can change it into different derivatives. These derivatives can be active or inactive. One important derivative is methyl jasmonate (MeJA). MeJA is a volatile compound that can move through the air to signal other plants. Another key form is JA-Ile. This is created when jasmonic acid is conjugated with the amino acid isoleucine. Research suggests that JA-Ile is involved in most jasmonate signaling. The plant can also undergo decarboxylation to produce cis-jasmone.

The history of these molecules began with the study of scents. In 1962, researchers isolated methyl jasmonate from jasmine oil. This oil comes from the plant *Jasminum grandiflorum*. This discovery allowed scientists to understand the molecular structure of jasmonates. Later, in 1971, Alderidge and colleagues isolated jasmonic acid itself. They found it in a fungus called *Lasiodiplodia theobromae*. These discoveries laid the groundwork for our modern understanding of plant hormones.

Jasmonates play many diverse roles in plant life. When a plant is wounded by an insect, JA biosynthesis is rapidly activated. In tomato plants, this produces defense molecules that inhibit leaf digestion in insect guts. JA is also linked to cell death and leaf senescence, which is the aging of leaves. It can induce mitochondrial death by causing the accumulation of reactive oxygen species (ROSs). These molecules disrupt membranes and cause apoptosis, or programmed cell death. This helps the plant limit the spread of infections.

Some plants have even repurposed this pathway for unique behaviors. The Venus flytrap uses jasmonate signaling to manage its carnivory. The hormone helps signal the closing of the traps. It also controls the release of enzymes and nutrient transporters used for digestion.

However, not all carnivorous plants use this system. Butterworts are different and may use methods to regulate enzymes that do not depend on JA.

Inside the cell, the jasmonate pathway works like a sophisticated on-off switch. This mechanism involves proteins called JAZ, which limit the activity of transcription factors. When JA is absent, JAZ proteins bind to these factors and keep them inactive. When JA or its derivatives arrive, they trigger the degradation of JAZ. This process is mediated by a protein called COI1. COI1 is part of an SCF complex that acts as a co-receptor. The JA-Ile molecule binds to both COI1 and a specific motif on the JAZ protein. Once the JAZ protein is removed, transcription factors like the MYC family are freed. These factors then activate the specific genes needed for the plant's response.