About this Research Topic
Acid soils occupy more than 30% of arable lands worldwide. Certain agricultural production systems, acid precipitation and excessive use of nitrogen fertilizers can accelerate soil acidification and limit productivity. Acid soils present many stresses to plants but prime among these is the increased prevalence of soluble aluminum cations (Al3+) which inhibit root growth and development and restrict the acquisition of water and nutrients. Agricultural practices can be modified to slow acidification but the regular application of lime remains the most effective way of correcting soil pH. However, for many farmers this option is not always possible due to cost, availability of resources or other infrastructural limitations. Even when lime is applied its movement down the profile is so slow that subsoil pH can take years to change. Farmers are often left with few options but to grow crops that are better adapted to acid soils while doing what they can to ameliorate the acidity. Therefore, it is of great importance to understand the mechanisms of plant-aluminum interactions in acid soils.
Although it is recognized that root apex is the major site of Al3+, it remains controversial whether Al toxicity occurs apoplastically or symplastically. At cellular levels, Al may target many sites simultaneously because it has strong affinity to electron donors which many biological macromolecules comprise. On the other hand, some strategies that plants have evolved for combating aluminum stress have already been described in wheat and barley as well as the model species Arabidopsis and rice. Although the most well-documented Al resistance mechanism is C2H2-type zinc finger transcription factor STOP1/ART1-mediated expression of Al resistance genes, many details of these mechanisms are unclear and very likely others remain to be discovered. Furthermore, how plant cells sensing and signaling Al toxicity, which in turn activates plant defense response is still in infancy. The rapid development of analytical tools and whole-genome sequencing provides new opportunities for unraveling these mechanisms and identifying novel ones. Novel strategies can then be developed for improving crops yields on acid soils either through traditional breeding practices or with biotechnology.
This Research Topic aims at improving our understanding on how aluminium adversely affects plant growth especially root growth and development, and the mechanisms by which plants resist harmful effects of aluminum. It welcomes studies addressing the biochemical, physiological, genetic, genomic, or molecular level of plant-aluminum interactions. In addition, it will cover the mechanisms by which acid soils impact plant nutrition. We warmly welcome reviews, mini-reviews and original articles.