The mechanisms behind the contrasting responses to waterlogging in black-grass (Alopecurus myosuroides) and wheat (Triticum aestivum)

A highly conserved ABCG transporter mediates root-soil cohesion in Arabidopsis

Identifying plant molecular mechanisms that mediate root-substrate interactions might offer potential solutions to soil erosion, especially in crop fields, where agricultural practices lead to soil loss. Mutants of the Arabidopsis (Arabidopsis thaliana) ATP-Binding Cassette G 43 (ABCG43) transporter gene show enhanced root-substrate cohesion, even though their root micro- and macro-structures are similar to those of wild-type Arabidopsis. We used genetic, biochemical, and functional methods to characterize the substrate-binding effects of changes in ABCG43 expression, including differences in exudate composition, and phylogenetic analyses to explore the evolutionary history of ABCG43 in land plants. Exudates from roots of the abcg43 mutant bound more soil and growing medium, and there were significant differences in abcg43 root exudate composition compared with the wild type. These results suggest that ABCG43 normally functions to mediate root exudates that affect root-substrate cohesion. Phylogenetic analysis showed that ABCG43 is highly conserved in plants, including in agriculturally important crop species. These results provide evidence that ABCG43 is a promising molecular target for developing crop plants with enhanced root-soil cohesion.

Flooding stress and responses to hypoxia in plants

In recent years, research on flooding stress and hypoxic responses in plants has gathered increasing attention due to climate change and the important role of O2 in metabolism and signalling. This Collection of Functional Plant Biology on 'Flooding stress and responses to hypoxia in plants' presents key contributions aimed at progressing our current understanding on how plants respond to low-O2 conditions, flooding stress and a combination of stresses commonly found in flooded areas. The Collection emphasises the characterisation of diverse plant responses across different developmental stages, from seed germination to fully developed plants, and under different water stress conditions ranging from waterlogging to complete submergence, or simply low-O2 conditions resulting from limited O2 diffusivity in bulky tissues. Additionally, this Collection highlights diverse approaches, including eco-physiological characterisation of plant responses, detailed descriptions of root anatomical characteristics and their surrounding microenvironments, evaluation of the seed microbiota under flooding stress, the modification of gene expression, and evaluations of diverse germplasm collections.