A Way of Increasing Growth Rate of Plants

Now British scientists have discovered a way of increasing growth rate of many staple vegetables using a naturally occurring plant protein that regulates cell division. The results have so far been demonstrated only in tobacco, which is used as a model species because of the ease of transformation (introduction of new genes), so the transfer and application to other species remains to be proven. This project has so far been confined to inserting a gene into the tobacco from a small weed plant arabidopsis the potential is enormous because this belongs to the very extensive brassica family that includes some of the most ubiquitous vegetables such as cabbage, cauliflower and brussels sprouts. In addition the tobacco family, solanaceae, includes the potato, tomato, peppers and aubergines.

These findings attracting great attention from the farming industry because

• these findings may have for potentially shortening the time to harvest,
• giving great flexibility of sowing time and faster crop rotation during a single growing season,
• extending the geographical zones in which crops can be grown, or increasing the reliability of cropping.

The Cambridge team, led by Dr.Jim Murray, has discovered the CycD family of genes from arabidopsis. In this the plant D-type cyclins respond to extracellular signals such as sugar availability to control the point at which cells become committed to division during the cell cycle. The Scientists team has found that during the cell-division cycle, a complex process takes place in which specific protein complexes not only control the wide ranging chemical activity in the cell but also interact with the cell’s structural machinery. They further discovered that modifying tobacco, with the arabidopsis CycD2 gene leads to faster growth.

This is measured as biomass accumulation, height and root development and improved vigour in the field. This proved to be very impressive, in that four weeks after germination the altered plants were up to twice the size of the control plants. These plants produced new leaf organs more rapidly and because they reached maturity more quickly, they flowered up to two weeks earlier. The arabidopsis Cyc2 protein associates with a tobacco CDK partner, forming a biochemically active complex that can drive the cell cycle. Increased levels of Cyc2-CDK complexes enhance plant growth by accelerating the rate at which new cells are produced in the meristems.

Agri-Scientists