Osmoregulation – Metabolic OsmoRegulation in Pollen
Plants are quite frugal organisms living on a simple diet of light, CO2 and water with a few ions but produce the majority of the food for an increasing global population. Shortage in any of these ‘plant nutrients’ will definitely result in lower crop yields and less food for humans. Recent prospective scenarios for agriculture forecast water shortages due to climate change and at the same time, increased water consumption for agricultural production of human nourishment (data on FAO webpages: FAOSTAT and AQUASTAT).
The supply of water during the plant’s life is one of the most essential parameters that control crop yield. Limited water supply and a low water potential will cause short- and long-term changes in plant growth and development, e.g. stomata closure and accumulation of solutes, respectively, to retain water and to counteract damaging effects of tissue dehydration. A major challenge for basic plant research will be to understand how plants use water in their organs and how they adapt to water shortages to allow targeted improvements for crop plants in the future. In addition to plant growth, fertilization, especially the male gametophyte (pollen), is highly sensitive to drought stress and failure in fertilization directly reduces crop yields due to lower production of seeds and fruits. So far, we do not know how pollen and the pollen tube in particular, adapt to reduced water availability in the stigma tissue because it needs to take up water continuously to elongate on its way to the ovule.