Bridging Molecular Insights and Agronomic Innovations: Cutting-Edge Strategies for Overcoming Boron Deficiency in Sustainable Rapeseed Cultivation

Abstract

Boron (B) is an essential micronutrient for the growth, development, and maintenance of cellular integrity in vascular plants, and is especially important in cell wall synthesis and reproductive development. Rapeseed (Brassica napus L.), one of the dominant oil crops globally, has a high boron demand and its yield is dramatically decreased under B-deficiency conditions. Rapeseed, which is very sensitive to boron deficiency, suffers from reduced growth and reproductive development, ultimately causing severe yield losses. Here, we reviewed the present state of knowledge on the physiological function of boron in rapeseed, mechanisms of boron uptake and transport, specific effects of boron deficiency in rapeseed, and approaches to alleviate boron deficiency in rapeseed at the agronomical and molecular levels. A specific focus is given to recent molecular breakthroughs and agronomic approaches that may improve boron efficiency. The review focuses on practices that may alleviate the problems caused by boron-deficient soils by investigating the genetic and physiological mechanisms of boron tolerance. In summary, this review describes the integration of molecular information with practical agronomy as an important aspect of breeding future nutrient-efficient rapeseed cultivars that can sustain increasing yields while being cultivated in regions with boron-deficient soils.

Keywords: BORs; NIPs; boron; rapeseed; transporters.

Figure 1

Effects of boron deficiency on rapeseed (Brassica napus), highlighting key symptoms such as stunted root growth, thickened and brittle stems, poor flower and seed formation, leaf deformation with chlorosis, reduced pod and seed production, and decreased oil content. Severe boron deficiency leads to necrosis of root tips, structural weaknesses, and increased susceptibility to diseases, ultimately reducing plant vigor and yield.

Figure 2

Boron uptake and transport in plants through facilitated and passive mechanisms. Boron is primarily absorbed as boric acid via passive diffusion in the roots, driven by transpiration flow. In conditions of low boron availability, active transport mechanisms involving boron transporters facilitate its uptake. Once inside the plant, boron moves through the xylem to areas of high demand, supporting critical functions such as cell wall integrity, reproductive development, and nutrient transport (adapted from [49]).

Figure 3

Proposed model explaining the differential responses to B deficiency in efficient rapeseed genotypes. Efficient genotypes exhibit enhanced boron uptake, maintain better root growth, and adapt by optimizing internal boron transport to critical tissues. These genotypes show improved flower and seed formation, reduced structural damage, and maintained higher yield under boron-deficient conditions.