Differential expression of the TFIIIA regulatory pathway in response to salt stress between Medicago truncatula genotypes1[W]
Differential expression of the TFIIIA regulatory pathway in response to salt stress between Medicago truncatula genotypes1[W]
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DOI：
10.1104/pp.107.106146
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发表时间：
2007-12-01
期刊：
影响因子：
7.4
通讯作者：
Sousa, Carolina
中科院分区：
文献类型：
--
作者：
de Lorenzo, Laura;Merchan, Francisco;Sousa, Carolina
土壤盐分是作物（包括豆科植物）最重要的非生物胁迫之一。这些植物可以与固氮土壤细菌建立根共生关系，并且能够在贫氮土壤中生长。蒺藜苜蓿品种对盐土等环境条件表现出多种适应性反应。我们比较了蒺藜两种基因型（108-R 和 Jemalong A17）根系生长对盐胁迫的响应差异。 Jemalong A17 比 108-R 更能耐受盐胁迫，根系和结瘤反应与介质的氮状态无关。使用包含 384 个与胁迫反应相关的基因的专用宏阵列来比较这些基因型在盐胁迫期间的根基因表达。一些可能与这些植物对盐胁迫的对比细胞反应相关的基因被鉴定为即使在没有胁迫的情况下也在更耐受的基因型中表达。其中，非生物胁迫相关的 COLD-REGULATEDA1 基因的同源物和 TFIIIA 相关转录因子 (TF) MtZpt2-1，已知可调节前一个基因。在 Jemalong A17 植物中发现了两个 MtZpt2 TF（MtZpt2-1 和 MtZpt2-2），与 108-R 相比，它们在根中的表达增加。这些转录因子在敏感基因型 108-R 中过度表达，但在 Jemalong A17 中则不然，导致盐胁迫下根部生长增加，表明该途径在这些蒺藜蒺藜基因型对盐胁迫的适应性反应中发挥作用。
Soil salinity is one of the most significant abiotic stresses for crop plants, including legumes. These plants can establish root symbioses with nitrogen-fixing soil bacteria and are able to grow in nitrogen-poor soils. Medicago truncatula varieties show diverse adaptive responses to environmental conditions, such as saline soils. We have compared the differential root growth of two genotypes of M. truncatula (108-R and Jemalong A17) in response to salt stress. Jemalong A17 is more tolerant to salt stress than 108-R, regarding both root and nodulation responses independently of the nitrogen status of the media. A dedicated macroarray containing 384 genes linked to stress responses was used to compare root gene expression during salt stress in these genotypes. Several genes potentially associated with the contrasting cellular responses of these plants to salt stress were identified as expressed in the more tolerant genotype even in the absence of stress. Among them, a homolog of the abiotic stress-related COLD-REGULATEDA1 gene and a TFIIIA-related transcription factor (TF), MtZpt2-1, known to regulate the former gene. Two MtZpt2 TFs (MtZpt2-1 and MtZpt2-2) were found in Jemalong A17 plants and showed increased expression in roots when compared to 108-R. Overexpression of these TFs in the sensitive genotype 108-R, but not in Jemalong A17, led to increased root growth under salt stress, suggesting a role for this pathway in the adaptive response to salt stress of these M. truncatula genotypes.