Lizards growing their lost tail, zebrafish healing its wounded heart are perfect examples of the remarkable feet of regeneration certain animals possess. Plants are known to regenerate lost tissues or organs throughout their bodies. But how to do they do it? A new research has identified a protein that helps plant roots regrow its cut tips.
An international team of researchers lead by Prof. Kalika Prasad, from the School of Biology at the Indian Institute of Science Education and Research (IISER) Thiruvananthapuram has pointed out that a protein called PLETHORA 2 (PLT 2) was the essential ingredient for primary and lateral root regeneration.
They studied a road-side plant of the mustard family and noticed that within eight hours of cutting its root tip, a high build-up of the protein at the site of damage. Using real-time live imaging the team was able to track the behaviour of the protein and found that the protein was distributed in the form of a gradient with the highest concentration in the root tip.
The team also noted that the entire plant root was not competent to regenerate and it was confined only to the tip of the root. They then demonstrated that by delivering the PLT2 protein, regeneration can be triggered even from non-competent root cells, which have long ago ceased to divide. They add that the protein works only at the right dose and exposure beyond the threshold was found to reduce the regeneration potential.
Agricultural benefits
“This regeneration is of immense importance to agronomically important plant species like carrot, radish or beetroot, in which the edible part is the primary root. Similar to other plants, these crops encounter damage to their primary root tips during growth and PLT2 protein can enable quick regeneration in such cases,” explains Kavya Durgaprasad, Ph.D. scholar at the institute and first author of the paper published in Cell Reports.
She adds that during the early stages of plant growth, the plant relies only on the primary root and any damage if not regenerated will halt the further growth of the root, which can prove very detrimental to the plant. The newly identified protein can be used to address these issues.
Shoot system study
Aerial organs such as leaves and stems often encounter injuries and their quick repair is essential for the survival of plants. Interestingly, members of the PLETHORA proteins are known to repair such damages and allow the plant to restore their growth.
Currently, the team is engaged in understanding how tissues disconnected in the shoot because of injuries (such as high wind or rain) regenerate and find their paths to get reunited.
“The most important message for members of the animal kingdom such as humans, who have lost the ability to regenerate is that the secret of regeneration may not lie only in finding novel genes from animals that are capable of regenerating their organs but most importantly the regulation of existing genes,” adds Prof. Prasad.
