Recently, one of the highest ranking scientific journals – Proceedings of the National Academy of Sciences of the USA (PNAS) published a paper on the key role of the plant hormone ethylene for the growth of the plants. First author of the publication b y the group of Dr. Dominique Van Der Straeten from the Laboratory of Functional Plant Biology, VUB Ghent, Belgium is our colleague Dr. Irina Vaseva from the Institute of Plant Physiology and Genetics!
This is a significant achievement! Too rare, not to say more, there is a paper in plant biology area of PNAS with first author from Bulgaria!
Let us paraphrase the classical saying “this year a paper in PNAS from international lab – next year – from a national one”J!
What is it all about? The authors show that ethylene acts as a “postman” bringing the message to the “doorstep” of the plants.
It is widely accepted that optimal plant growth and development is of uttermost importance for modern agriculture. In the next decades, climate models predict that world-wide more frequent and severe extreme events (spring frost, summer heat waves, extended drought periods or floods etc.) will be with devastating consequences for the agriculture. In this respect, to study the mechanisms for coping with unfavorable environment is important both from ecological and economical point of view!
Plant growth and development depend on signals perceived in distinct cell types where hormonal inputs are transformed into orchestrated responses triggering a plethora of physiological processes. Unlike the other plant growth regulators (plant hormones), ethylene is a fairly simple hydrophobic molecule which can freely enter cells via diffusion. Therefore, studies on the cell type specificity of its action is very important and at the same time, a real challenge!
Ethylene is a gaseous hormone with growth-inhibiting function and it is among the major players in generating stress responses towards adverse environmental conditions.
By tissue specific expression of two proteins (negative regulators of the signaling cascade), it became possible to selectively disrupt the ethylene signal in different cell types without affecting its biosynthesis.
This engineered approach demonstrated that the signals coming from environment are somehow “caught”by ethylene at “the doorstep” of the plant – the epidermis and the growth-restriction action takes place by dampening the effect of auxins in the outermost cell layer, and subsequently drives growth of the inner tissues.
In other words the epidermis is not only the plant “dress”, but it also tightens them, restricting their growth under unfavorable conditions!
The identification of epidermis as the main site for growth inhibiting action of ethylene opens significant possibilities for the development of new biotechnological strategies. By precise tissue-specific control of plant growth regulation, it will be possible to increase stress tolerance or improve desired traits in economically important crops.
This is a step towards better understanding of the mechanisms by which different hormones coordinate their action in order to help the plants to adapt to constantly changing environment. This could be further implemented in development of novel biotech strategies.
Vaseva I. et al., The plant hormone ethylene restricts Arabidopsis growth via the epidermis PNAS April 24, 2018. 115 (17) E4130-E4139; published ahead of print April 11, 2018. https://doi.org/10.1073/pnas.1717649115
