A Transcriptomic Network Underlies Microstructural and Physiological Responses to Cadmium in Populus x canescens1[C][W]
A Transcriptomic Network Underlies Microstructural and Physiological Responses to Cadmium in Populus x canescens1[C][W]
复制标题
DOI：
10.1104/pp.113.215681
复制
发表时间：
2013-05-01
期刊：
影响因子：
7.4
通讯作者：
Luo, Zhi-Bin
中科院分区：
文献类型：
--
作者：
He, Jiali;Li, Hong;Luo, Zhi-Bin
3号杨树皮组织对镉的积累能力较强，但其微观结构、转录和生理反应机制尚不清楚。通过组织化学分析、电子显微镜观察、X射线能谱分析、转录和生理分析等手段，加深了我们对Cd在P.x3中的积累和解毒的了解。Cd主要分配到树皮韧皮部，亚细胞Cd区域化主要发生在韧皮部细胞的液泡中。在Cd胁迫下的P.x3油菜树皮中，涉及微观结构变化、营养和初级代谢的变化以及胁迫反应刺激的转录本显示了显著的差异表达。大约48%的差异调控转录本形成了一个共调控网络，其中43个HUB基因在不同生物学过程之间的串扰中发挥核心作用，并在协调P.x3斑潜蝇树皮对镉的转录调控中发挥核心作用。生理读数反映了3号斑潜蝇树皮中的镉转录组。镉的积累导致树皮中总氮、磷、钙的减少和硫的增加。镉抑制光合作用，导致碳水化合物水平下降。镉诱导的氧化应激和抗氧化剂，包括游离脯氨酸、可溶性酚类、抗坏血酸和硫醇化合物。这些结果表明，协调的微结构、转录和生理调控可能维持Cd在P.x3油菜树皮中的过度积累，并为工程木本植物的植物修复提供新的见解。
Bark tissue of Populus 3 canescens can hyperaccumulate cadmium, but microstructural, transcriptomic, and physiological response mechanisms are poorly understood. Histochemical assays, transmission electron microscopic observations, energy-dispersive x-ray microanalysis, and transcriptomic and physiological analyses have been performed to enhance our understanding of cadmium accumulation and detoxification in P. x 3 canescens. Cadmium was allocated to the phloem of the bark, and subcellular cadmium compartmentalization occurred mainly in vacuoles of phloem cells. Transcripts involved in microstructural alteration, changes in nutrition and primary metabolism, and stimulation of stress responses showed significantly differential expression in the bark of P. x 3 canescens exposed to cadmium. About 48% of the differentially regulated transcripts formed a coregulation network in which 43 hub genes played a central role both in cross talk among distinct biological processes and in coordinating the transcriptomic regulation in the bark of P. x 3 canescens in response to cadmium. The cadmium transcriptome in the bark of P. x 3 canescens was mirrored by physiological readouts. Cadmium accumulation led to decreased total nitrogen, phosphorus, and calcium and increased sulfur in the bark. Cadmium inhibited photosynthesis, resulting in decreased carbohydrate levels. Cadmium induced oxidative stress and antioxidants, including free proline, soluble phenolics, ascorbate, and thiol compounds. These results suggest that orchestrated microstructural, transcriptomic, and physiological regulation may sustain cadmium hyperaccumulation in P. x 3 canescens bark and provide new insights into engineering woody plants for phytoremediation.