Sugar Beet Engineering Research Center of Heilongjiang Province, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, China.
Sugar Beet Engineering Research Center of Heilongjiang Province, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, 150080, China.
Plant Physiol Biochem. 2023 Apr;197:107619. doi: 10.1016/j.plaphy.2023.02.049. Epub 2023 Mar 8.
Boron (B) deficiency and consequent limitation of plant yield and quality, particularly of sugar beet (Beta vulgaris L.) has emerged as a maior problem,which is exacerbating due to cultivar dependent variability in B deficiency tolerance. Pertinently, the current study was designed to elucidate the physiological and molecular mechanisms of B deficiency tolerance of sugar beet varieties KWS1197 (B-efficient variety) and KWS0143 (B-inefficient variety). A hydroponic experiment was conducted employing two B levels B0.1 (0.1 μM L HBO, deficiency) and B50 (50 μM L HBO, adequacy). Boron deficiency greatly inhibited root elongation and dry matter accumulation; however, formation of lateral roots stimulated and average root diameter was increased. Results exhibited that by up-regulating the expression of NIP5-1, NIP6-1, and BOR2, and suppressing the expression of BOR4, cultivar KWS1197, in contrast to KWS0143, managed to transfer sufficient amount of B to the aboveground plant parts, facilitating its effective absorption and utilization. Accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS) was also mellowed in KWS1197, as well as the oxidative damage to root cells via preservation of the antioxidant enzyme system. Additionally, the expression of essential enzymes for biosynthesis of phytohormone (PYR/PYL) and lignin (COMT, POX, and CCoAOMT) were found to be highly up-regulated in KWS1197. Deductively, through effective B absorption and transportation, balanced nutrient accumulation, and an activated antioxidant enzyme system, B-efficient cultivars may cope with B deficiency while retaining a superior cellular structure to enable root development.
硼（B）缺乏以及由此导致的植物产量和品质下降，特别是甜菜（Beta vulgaris L.），已经成为一个主要问题，而且由于品种对 B 缺乏耐性的差异，这种情况正在加剧。恰在此时，本研究旨在阐明 KWS1197（B 高效品种）和 KWS0143（B 低效品种）对 B 缺乏耐性的生理和分子机制。采用水培实验，设置了两个 B 水平 B0.1（0.1 μM L HBO，缺乏）和 B50（50 μM L HBO，充足）。硼缺乏极大地抑制了根伸长和干物质积累；然而，侧根的形成受到刺激，平均根直径增加。结果表明，通过上调 NIP5-1、NIP6-1 和 BOR2 的表达，以及抑制 BOR4 的表达，与 KWS0143 相比，品种 KWS1197 能够将足够的 B 转移到地上植物部分，促进其有效吸收和利用。KWS1197 中丙二醛（MDA）和活性氧（ROS）的积累也得到了缓解，同时通过保护抗氧化酶系统，减轻了根细胞的氧化损伤。此外，还发现与 KWS0143 相比，必需酶的表达对于植物激素（PYR/PYL）和木质素（COMT、POX 和 CCoAOMT）的生物合成高度上调。推断起来，通过有效的 B 吸收和运输、平衡的养分积累以及激活的抗氧化酶系统，B 高效品种可能在保持卓越的细胞结构以促进根发育的同时应对 B 缺乏。
