destroy and build

Spikes in the prices of tomatoes that occur from time to time - due to heat waves, or for other reasons - remind the residents of the country how unsafe our food sources are

Spikes in the prices of tomatoes that occur from time to time - due to heat waves, or for other reasons - remind the residents of the country how uncertain our food sources are: any climate change could instantly create a severe shortage of basic foodstuffs. Even if we ignore the impact of natural disasters, ensuring a regular supply of food in the 21st century will not be an easy task: the population of the Earth continues to grow, but the area of ​​land devoted to agriculture remains fairly constant, a situation that will undoubtedly lead to food shortages, which will be further aggravated by global warming.

"The continuation of the green revolution is extremely essential," says Prof. Robert Flor from the Department of Plant Sciences at the Weizmann Institute of Science, referring to the improvement of the crop which saved humanity from starvation in the second half of the 20th century. "Adapting agriculture to the current needs of the world is a constant war. To win it, we must act with momentum, without letting up."

The need to feed humanity is an especially big challenge in light of the fact that a huge proportion of the world's harvest - over 30%, to be exact - is regularly lost due to pests, diseases and changes in the weather. Prof. Flor and the members of his research group at the Weizmann Institute of Science are conducting research, which may help increase the yield by reducing the percentage of losses. The laboratory mainly focuses on research designed to understand - and ultimately increase - the mechanisms of the plants' natural resistance to a variety of hazards.

Recently, in collaboration with scientists from Australia, the members of Prof. Flore's research group took an important step in this direction. The scientists deciphered a molecular switch that controls a mechanism essential to the growth and survival of the plant: a mechanism that kills individual cells of the plant through the activation of disintegrating enzymes called proteases, which destroy important proteins in the cell. These enzymes come into play when the plant tries to stop the spread of the disease, or tries to extract nutrients from old leaves. But in order for the plant to survive, the proteases must act exactly at the required rate: at a speed that will allow the disease to be stopped, but also slowly enough, so that this rescue operation does not destroy the entire plant.

In his new research, Prof. Flor identified a potential "pacemaker", which determines the speed at which the proteases carry out their "destruction of the beaver": this is a molecule that belongs to a family of proteins called serpins (SERPINS). The molecule, called AtSerpin1, acts like a molecular mousetrap: when the destruction needs to be slowed down, it "captures" a certain protease and disables its action. In this way, AtSerpin1 determines the rate of cell integrity in the plant. The research, the results of which were published in the Journal of Biological Chemistry, was carried out by (then) research student Dr. Nardi Lampel, Dr. Ofra Bodai-Hadrian and Dr. Olga Davidov, from the Department of Plant Sciences at the Weizmann Institute, in collaboration with scientists from Australia: Tom G 's and Dr. Thomas Roberts from Macquarie University, and Dr. Stephen Haroff and Prof. Paul Cormey from the University New South Wales.

It seems that the molecular "pacemaker" is essential and exceptionally effective, since it has been in use for at least a billion years - a sure sign of evolutionary success. The "pacemaker" is found in both plants and animals, and its origins can already be discovered in single-celled organisms with a nucleus (the ancestors of both plants and animals). In mammals, including humans, the serifin-controlled proteases perform various roles in the immune system, blood coagulation and fetal development.

The fact that in animals, including humans, many actions of the proteases are controlled by serapins, has been known for many years. But the current study is the first to identify the "pacemaker" seraphin and its protease in plants. The research was done on the plant called Arabidopsis, which is close to the mustard plant, which is a convenient model for research, but the analysis of the plant genome shows that the findings may be relevant to the entire plant kingdom. These findings open a new direction of research, with the aim of discovering additional "pacemakers", that is, other serphin molecules that control the activity of different proteases. The ultimate goal: to deeply understand the plant's natural defenses, which may help create stronger plants, thus minimizing crop loss.

Prof. Flor emphasizes that this is a most urgent goal in the entire world: "Israel can be an example of the global need to increase crops. A number of typical factors - overdensity of the population, and a lack of water and land suitable for crops - make agriculture in Israel particularly vulnerable to environmental effects."

Invents a job for him
As a child growing up in Brooklyn, New York, Prof. Robert Flore was attracted to what was missing in the big city: the plants, nature, the land. He was fascinated by the process by which plants use sunlight to produce energy and food, which enable the existence of the animal world. The following quote from Rambam's words summarizes for him the contribution of plant researchers to "Tikhon Olam": to understand how plants work, and to improve them to prevent hunger and the well-being of man. Among the types of giving to those in need, Rambam enumerates: "There is no greater virtue than that - inventing a job for him, To strengthen his hand until he doesn't have to fight and doesn't ask." Laws of Gifts to the Poor, Chapter 10, Sefer Zeraiim, Mishna Torah to the Maimonides.