An arginine decarboxylase gene PtADC from Poncirus trifoliata confers abiotic stress tolerance and promotes primary root growth in Arabidopsis.
An arginine decarboxylase gene PtADC from Poncirus trifoliata confers abiotic stress tolerance and promotes primary root growth in Arabidopsis.
复制标题
DOI：
10.1093/jxb/erq463
复制
发表时间：
2011-05
影响因子：
6.9
通讯作者：
Jing Wang;Pei Sun;Chun-Li Chen;Yin Wang;Xing-zheng Fu;Ji-Hong Liu
中科院分区：
文献类型：
--
作者：
Jing Wang;Pei Sun;Chun-Li Chen;Yin Wang;Xing-zheng Fu;Ji-Hong Liu
精氨酸脱羧酶（ADC）是逆境条件下多胺合成的重要酶。本研究分离了枳壳ADC基因（PtADC），该基因以单拷贝形式存在。PtADC的转录水平上调低温和脱水。在拟南芥ADC突变体adc 1 -1中过量表达PtADC可促进转基因株系中腐胺的合成，气孔密度恢复到野生型。与野生型和突变体相比，转基因株系表现出对高温、脱水、长期干旱和低温胁迫的抗性增强。在转基因株系中的活性氧（ROS）的积累在胁迫下明显降低，但当转基因植株在胁迫处理之前用ADC抑制剂D-精氨酸处理时，ROS清除能力受到损害。此外，在正常和胁迫条件下，转基因株系的根都比野生型和突变体长，这与更大的细胞数量和根分生区的长度一致。两者合计，这些结果表明，PtADC参与耐受多种胁迫，其功能可能是由于，至少部分地，有效的ROS消除和其对根系生长的影响，有利于耐旱性。
Arginine decarboxylase (ADC) is an important enzyme responsible for polyamine synthesis under stress conditions. In this study, the gene encoding ADC in Poncirus trifoliata (PtADC) was isolated and it existed as a single-copy member. Transcript levels of PtADC were up-regulated by low temperature and dehydration. Overexpression of PtADC in an Arabidopsis thaliana ADC mutant adc1-1 promoted putrescine synthesis in the transgenic line and the stomatal density was reverted to that in the wild type. The transgenic line showed enhanced resistance to high osmoticum, dehydration, long-term drought, and cold stress compared with the wild type and the mutant. The accumulation of reactive oxygen species (ROS) in the transgenic line was appreciably decreased under the stresses, but ROS scavenging capacity was compromised when the transgenic plants were treated with the ADC inhibitor D-arginine prior to stress treatment. In addition, the transgenic line had longer roots than the wild type and the mutant under both normal and stressful conditions, consistent with larger cell number and length of the root meristematic zone. Taken together, these results demonstrated that PtADC is involved in tolerance to multiple stresses, and its function may be due, at least partly, to efficient ROS elimination and to its influence on root growth conducive to drought tolerance.