Cell wall signalling in flooded plants

Abstract

You may have noticed that giving your houseplants too much water is harmful to them. It limits their ability to take up oxygen from the air, which causes them to suffocate. The symptoms are that their leaves will hang down and decay of the roots. Excessive watering in the form of floods can destroy crops in the same way that it can hurt your houseplant. Floods have major consequences for the quantity and quality of agricultural food production. According to the Food and Agriculture Organisation of the United Nations (FAO), floods contributed to 65% of crop damage and loss induced by natural disasters between 2006 and 2016. Heavy rainfalls, causing severe floods, are more likely to happen in the future due to the impacts of climate change. Our current and future food supply is seriously threatened by the impacts of floods. Therefore, we must develop innovative agricultural technologies to combat crop yield loss caused by water stress.

One area of research that can help with this goal is the development of new varieties of crops that are more resistant to long-term floods. When plants experience floods, they develop all kinds of adaptations that help them to survive. For example, plants develop new organs that help them prevent suffocation. Understanding how plants perceive flooding stress and how this perception results in the development of these adaptations is necessary knowledge to develop flood-resistant crops. For example, this knowledge would allow opportunities to arise for future researchers to develop new crops that respond faster and more intensely to floods.

One mechanism that plants use to become aware of their surroundings is by determining the status of their cell walls. It uses the cell wall as a sensing tool to detect harmful growth conditions, such as hot and cold temperatures and drought conditions. Thanks to these mechanisms, plants can respond quickly to these stresses, allowing them to survive these harmful conditions. Although the cell wall status plays a significant role in the perception of several damaging growth conditions, its role during flooding stress is hardly investigated. Therefore, we asked the question: “Are cell walls also involved in the perception of flooding stress in plants?”

To find an answer to this question, we searched the literature for potential cell wall sensing mechanisms that are active during floods. Here, we merged the expertise of two distinct research fields by combining the knowledge of (1) plant mechanisms and adaptations during floods and (2) plant cell wall sensing mechanisms. In this review, we concluded that there is enough evidence to believe thatsensing the cell wall status is needed for plants to undergo adaptations that help them plants to survive floods. The most prominent role is reserved for the cell wall component, pectin. We believe that during floods, the pectin changes in form. Consequently, we believe that this is perceived by the plant, and they undergo adaptions that protect them against floods. With this report, we contributed to the field of science by providing credible theories of potential explanations of how plants trigger adaptations during floods, which eventually contributes to the efforts to limit food loss caused by floods.