Malate secretion from the root system is an important reason for higher resistance of Miscanthus sacchariflorus to cadmium
Malate secretion from the root system is an important reason for higher resistance of Miscanthus sacchariflorus to cadmium
复制标题
根系分泌苹果酸是芒草对镉具有较高抗性的重要原因。
DOI：
10.1111/ppl.12526
复制
发表时间：
2017-03-01
影响因子：
6.4
通讯作者：
Jiang, Dean
中科院分区：
文献类型：
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作者：
Guo, Haipeng;Feng, Xue;Jiang, Dean
芒属植物是一种多年生禾本科植物，具有较强的重金属吸收能力，是一种很有前途的生物能源作物。然而，芒属植物对重金属的耐受机制尚不清楚。本研究以两种对镉（Cd）敏感性不同的芒属植物（Miscanthus sacchariflorus和Miscanthus floridulus）为材料，探讨其对Cd的耐受机制。在相同的Cd胁迫下，M.糖花苜蓿对Cd的耐性较强，生长较好，地上部和根系中Cd积累量较低。花卉。根系分泌物中苹果酸含量显著增加。而M. sacchariflorus在Cd处理后几乎没有变化。花卉。细胞Cd分析和通量数据表明，外源MA明显抑制了Cd的内流和积累，而阴离子通道抑制剂苯乙二醛（phenylglyoxal）有效地阻断了Cd诱导的MA分泌，增加了Cd的内流。表明MA分泌物可以通过减少Cd吸收来减轻Cd毒害。苹果酸脱氢酶（MsMDHs）和铝激活的苹果酸转运蛋白1（MsALMT1）基因在M.在Cd胁迫下，与M.花卉。结果表明，镉诱导的MA合成和分泌通过减少镉内流有效地减轻了镉的毒性。糖花。
Miscanthus is a vigorous perennial Gramineae genus grown throughout the world as a promising bioenergy crop and generally regarded as heavy metal tolerant due to its ability to absorb heavy metals. However, little is known about the mechanism for heavy metal tolerance in Miscanthus. In this study, two Miscanthus species (Miscanthus sacchariflorus and Miscanthus floridulus) exhibiting different cadmium (Cd) sensitivity were used to address the mechanisms of Cd tolerance. Under the same Cd stress, M. sacchariflorus showed higher Cd tolerance with better growth and lower Cd accumulation in both shoots and roots than M. floridulus. The malate (MA) content significantly increased in root exudates of M. sacchariflorus following Cd treatment while it was almost unchanged in M. floridulus. Cellular Cd analysis and flux data showed that exogenous MA application markedly restricted Cd influx and accumulation while an anion-channel inhibitor (phenylglyoxal) effectively blocked Cd-induced MA secretion and increased Cd influx in M. sacchariflorus, indicating that MA secretion could alleviate Cd toxicity by reducing Cd uptake. The genes of malate dehydrogenases (MsMDHs) and Al-activated malate transporter 1 (MsALMT1) in M. sacchariflorus were highly upregulated under Cd stress, compared with that in M. floridulus. The results indicate that Cd-induced MA synthesis and secretion efficiently alleviate Cd toxicity by reducing Cd influx in M. sacchariflorus.