Abstract
(Aims) Sugar beet is one of the most sensitive crops to boron and boron deficiency inhibits the root growth and causes hollow symptoms in beets. However, how the roots of boron efficient sugar beet variety adapt to the morphology, physiological, and transcriptome mechanisms of boron deficiency are rarely reported. (Method) Thus, the present study was carried out with B efficient sugar beet variety (H, KWS1197) and B inefficient variety (L, KWS0143), and two B levels i.e., B0.1 (0.1 μM H3BO3, deficiency) and B50 (50 μM H3BO3, control) were designed for hydroponic experiment. (Result) Boron deficiency reduced the total root length, root forks, and root biomass of sugar beet. Compared with L variety, H variety have higher boron transport coefficient, boron distribution ratio above ground, peroxidase and catalase activities, lower malondialdehyde content and reactive oxygen species accumulation. Transcriptome data showed that the two comparison groups, HB0.1 vs HB50 and LB0.1 vs LB50, were enriched for 537 and 257 differentially expressed genes, respectively. The H variety mainly induced and regulated the GO term enrichment associated with antioxidant and stress resistance. On the contrary, the L variety induced cell death and negative regulation of biological and metabolic processes. (Conclusion) B efficient variety specifically up-regulated boron deficiency response genes to activate the antioxidant enzyme system, promoted rational root configuration, and enhance plant growth anti-oxidation and resistance to boron deficiency. The results of this study serve as a theoretical basis of screening candidate genes that respond to boron deficiency and adaptation mechanism of boron deficiency.