Kim Jihye, Lee Won Je, Vu Tien Thanh, Jeong Chan Young, Hong Suk-Whan, Lee Hojoung
Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-Gu, Seoul, 136-713, Republic of Korea.
Department of Molecular Biotechnology, College of Agriculture and Life Sciences, Bioenergy Research Center, Chonnam National University, Gwangju, Republic of Korea.
Plant Cell Rep. 2017 Aug;36(8):1215-1224. doi: 10.1007/s00299-017-2147-7. Epub 2017 Apr 25.
The ectopic expression of AtDFR results in increased accumulation of anthocyanins leading to enhanced salinity and drought stress tolerance in B. napus plants. Flavonoids with antioxidant effects confer many additional benefits to plants. Evidence indicates that flavonoids, including anthocyanins, protect tissues against oxidative stress from various abiotic stressors. We determined whether increases in anthocyanins increased abiotic stress tolerance in Brassica napus, because the values of B. napus L. and its cultivation area are increasing worldwide. We overexpressed Arabidopsis dihydroflavonol-4-reductase (DFR) in B. napus. Increased DFR transcript levels for AtDFR-OX B. shoots correlated with higher anthocyanin accumulation. AtDFR-OX Brassica shoots exhibited lower reactive oxygen species (ROS) accumulation than wild-type (WT) shoots under high NaCl and mannitol concentrations. This was corroborated by 3,3-diaminobenzidine staining for ROS scavenging activity in 1,1-diphenyl-2-picryl-hydrazyl assays. Shoots of the AtDFR-OX B. napus lines grown in a high salt medium exhibited enhanced salt tolerance and higher chlorophyll content than similarly grown WT plants. Our observations suggested that the AtDFR gene can be effectively manipulated to modulate salinity and drought stress tolerance by directing to high accumulation of anthocyanins in oilseed plants.
AtDFR的异位表达导致花青素积累增加，从而增强了甘蓝型油菜植株对盐胁迫和干旱胁迫的耐受性。具有抗氧化作用的类黄酮为植物带来许多额外的益处。有证据表明，包括花青素在内的类黄酮可保护组织免受各种非生物胁迫源引起的氧化应激。我们研究了花青素的增加是否提高了甘蓝型油菜对非生物胁迫的耐受性，因为甘蓝型油菜在全球的种植面积和产量都在增加。我们在甘蓝型油菜中过表达了拟南芥二氢黄酮醇-4-还原酶（DFR）。AtDFR-OX甘蓝型油菜地上部DFR转录水平的增加与较高的花青素积累相关。在高NaCl和甘露醇浓度下，AtDFR-OX甘蓝型油菜地上部的活性氧（ROS）积累低于野生型（WT）地上部。在1,1-二苯基-2-苦基肼试验中，通过3,3-二氨基联苯胺染色检测ROS清除活性，证实了这一点。在高盐培养基中生长的AtDFR-OX甘蓝型油菜品系的地上部比同样生长的WT植株表现出更强的耐盐性和更高的叶绿素含量。我们的观察结果表明，通过调控AtDFR基因，可使油料作物中花青素大量积累，从而有效调节其对盐胁迫和干旱胁迫的耐受性。
