Expansins: roles in plant growth and potential applications in crop improvement

Abstract

Key messageResults from various expansin related studies have demonstrated that expansins present an opportunity to improve various crops in many different aspects ranging from yield and fruit ripening to improved stress tolerance.AbstractThe recent advances in expansin studies were reviewed. Besides producing the strength that is needed by the plants, cell walls define cell shape, cell size and cell function. Expansins are cell wall proteins which consist of four sub families; α-expansin, β-expansin, expansin-like A and expansin-like B. These proteins mediate cell wall loosening and they are present in all plants and in some microbial organisms and other organisms like snails. Decades after their initial discovery in cucumber, it is now clear that these small proteins have diverse biological roles in plants. Through their ability to enable the local sliding of wall polymers by reducing adhesion between adjacent wall polysaccharides and the part they play in cell wall remodeling after cytokinesis, it is now clear that expansins are required in almost all plant physiological development aspects from germination to fruiting. This is shown by the various reports from different studies using various molecular biology approaches such as gene achieve these many roles through their non-enzymatic wall loosening ability. This paper reviews and summarizes some of the reported functions of expansins and outlines the potential uses of expansins in crop improvement programs.

A maize phytochrome‐interacting factors protein ZmPIF1 enhances drought tolerance by inducing stomatal closure and improves grain yield in Oryza sativa

“…EXPANSIN is a cell wall protein that is involved in regulating the stomatal aperture and stomatal density (Lü et al ., ; Marowa et al ., ; Wei et al ., ; Zhang et al ., ). Our DGE results revealed that eight EXPANSIN genes were up‐regulated in ZmPIF1 ‐transgenetic rice (Table ).…”

Understanding the Remodelling of Cell Walls during Brachypodium distachyon Grain Development through a Sub-Cellular Quantitative Proteomic Approach

“…Expansins are secreted to the cell wall and have the ability to loosen plant cell walls in a non-enzymatic but pH-dependent manner, thus allowing cell expansion [48]. It was demonstrated in wheat that expansins play a major role in crop yield by affecting grain development and size [49].…”

Genome-wide identification of the expansin gene family in tobacco (Nicotiana tabacum)

“…They have also been associated with nutrient uptake and efficiency (Zhou et al 2014), abiotic and biotic stress tolerance Zhao et al 2011;Lü et al 2013). After looking closely at the various roles played by expansins in plants, Marowa et al (2016) have concluded that inclusion of expansins in plant breeding programs presents an opportunity to improve crops in various aspects. These include but are not limited to improving germination, leaf size, fruit growth and ripening and tolerance to abiotic and biotic stresses (Marowa et al 2016).…”