Camelia Bhattacharyya, Amity University Kolkata
Nitrogen fixation is a term we often use while mentioning legumes. Legumes are plants that contain Rhizobium bacteria inside their root nodules. These bacteria help in converting nitrogen into nitrites and nitrates which are further used by the plant. This entire process is how nitrogen fixation takes place. This process can also be used as an example of mutualism where both the living beings, the legumes and the rhizobium are helping each other and coexisting for their good. This process has another name, the root nodule symbiosis (RNS). This type of study regarding the colonization of the Sinorhizobium meliloti inside the roots of the Medicago truncatula has been recently studied by a group of researchers and amazing results have been brought to light, which show the role of a type of formin in fighting symbionts in legumes. Thus, it can be said that formins are the mastermind for fighting symbionts in legumes!
The roots of Medicago truncatula starts interacting with the rhizobium since their growing stage when the formation of the root hair is still on. During symbiotic infections, these root hairs associating rhizomes curls around to trap the symbiont. This type of action is common in different types of plants where the plants respond by swelling up or by branching. Recently the curling or rather the complete curling of the root hair is something of an invention when speaking of the legumes. And this invention states its properties in acting against infections, thus paving a broad way with entirely new scopes for those studying the plants and everything related to it.
A chamber termed the “infection chamber” is formed once the root hair has curled completely. This chamber further gives rise to a tube-like extension known as the “infection thread”. All these have been known to be carried out by actin, or more specifically, the rearrangements of actin and subapical bundle formations led by them. The dynamics of actin changes to create such a complex as shown in various mutants of the Medicago truncatula. This complex in the protoplasts is similar to the scar tissue in the kingdom Animalia. But there is a lot left to be studied about the biochemical reasons of such a complex. The very recent advancement done in this field shows the role of a symbiotic formin in the Nod-factor dependent changes which leads to further changes in the responses of the root hair to the symbiont, rhizobium. This formin has been named symbiotic formin 1 (SYFO1). It helps in creating a bridge between the cell wall, cell membrane and the cytoskeleton which further leads to the onset of the curling and thus the infection formation.
Further studies on the detailed biochemistry of the formin-mediated alterations in the root hair might result in opening a new way in creating bioengineered plants to fight infections by biomimicking the RNS mechanism, without the use of chemicals. This might be a better approach towards green biotechnology and pollution-free cultivation of crops.
References:
Liang P, Schmitz C, Lace B, Ditengou FA, Su C, Schulze E, Knerr J, Grosse R, Keller J, Libourel C, Delaux P-M, Ott T. Formin-mediated bridging of cell wall, plasma membrane, and cytoskeleton in symbiotic infections of Medicago truncatula. (2021) Current Biology 31, 1-8. doi:10.1016/j.cub.2021.04.002.
Retrons- A new promising Gene-editing tool
Anannya Roy, Amity University Kolkata CRISPR- Cas 9 gene-editing system, we all have heard of that isn’t it? A giant in Gene editing. Well here’s the thing- There is something even more interesting than that. Retrons: A group of researchers at Harvard University and Harvard Medical School have created a new gene-editing tool called Retron […]