Researchers have discovered the complex molecular processes that precede reproduction in flowering plants, and their results document a previously unknown molecular process that serves as a means of communication during fertilization.
Researchers have discovered the complex molecular processes that precede the reproductive process in flowering plants, and their results document a previously unknown molecular process that serves as a means of communication during fertilization. This was reported by Phys.org.
According to Professor Sheng Luan, senior author of the study and chair of the Department of Plant and Microbial Biology (PMB) at the University of California, Berkeley, USA, the exact mechanism of the signal researchers have previously eluded. “At the molecular level, this whole process is now clearer than ever,” Luan said.
Flowers reproduce by pollination, a process involving the transfer of pollen grains, small grains produced in the male organs of flowering plants from the flower’s stamens (the male fertilized organ) to the female reproductive organs, or fruit leaves.
The petal contains the stigma, an often sticky organ to which pollen containing male gametes is attached. Once the pollen has settled on the stigma, a tube of pollen grows into the ovule to facilitate the transfer of male reproductive cells to the ovule.
The seeds are formed after the pollen is transferred from the male part to the female part of the plant, and the seeds and fruits are formed after the fertilization process, and the egg turns into a seed when it is fertilized, and the ovary usually changes in a fruit.
A romantic journey to plant reproduction
In their study, the researchers relied on the plant “Mouse-ear Cress” (Arabidopsis thaliana), a type of small flowering plant that scientists are preparing as a botanical mouse, and this study identified a previously unknown molecular process that serves as ” a means of communication during fertilization and reproduction.
Luan said the researchers had previously recorded calcium waves before fertilization, noting that “they knew the calcium signal was important, but they did not know exactly how it was produced.”
To analyze how the calcium wave is produced by the female cell, Luan and colleagues provided a biosensor to detect calcium levels in a specific cell, looking for signals from the male parts that release calcium waves.
They found that pollen tubes emit several “small peptides” (short-chain amino acids) that can recognize peptide receptors on the surface of the female cell. Once activated, these receptors recruit the calcium channel to produce a wave of calcium that leads the pollen tube to the egg and initiates fertilization.
“You can compare it to a delivery service,” Luan explained. “We know the small peptide molecule serves as a signal to the female part of the flower, almost like knocking on a door to let her know that the pollen tube is here. . “
The calcium waves eventually cause the tube to break and release the male gametes once inside the egg, ensuring successful fertilization.
“In a way, they are basically committing suicide to release the male gametes,” Luan said. “Sometimes the female reproductive cell also dies to expose the egg so that it can converge and produce a new life. It’s kind of the romantic journey. Of plant reproduction.”
Rediscover molecular messages
The calcium channels identified in this study are unique in the case of plants, due to their great popularity in relation to diseases in humans. Researchers have developed drugs called calcium channel blockers that lower blood pressure and treat other conditions, such as chest pain and irregular heartbeat, as they work to prevent calcium from entering the cells of the heart and arteries, as it causes the heart and arteries to contract more forcefully. By blocking calcium, calcium channel blockers cause blood vessels to relax and open.
Therefore, the unveiling of this mechanism in plants is very interesting, and the use of this mechanism suggests that plants have a way of producing signals that differ from those in animals and humans, and can perform other vital functions.
Luan said researchers have been studying calcium channels for more than 30 years, which have revealed how to resist powdery mildew (a fungal disease that affects a variety of plants) or allow mechanical observation in root systems, but the biochemical effects thereof remained unknown until this study revealed activity of the chosen channel.
In addition to the potential commercial application, the results of this study highlight the ability of miraculous plants to communicate via molecular emissions.
According to Luan, understanding the complex molecular processes of fertilization can help improve economic yields of flowering plants. Other researchers or plant geneticists may use these findings to break the barrier between species, possibly opening the door to the production of new crop hybrids by cross-pollination.