Cadmium tolerance in Schinus molle trees is modulated by enhanced leaf anatomy and photosynthesis
Cadmium tolerance in Schinus molle trees is modulated by enhanced leaf anatomy and photosynthesis
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DOI：
10.1007/s00468-015-1322-0
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发表时间：
2016-06-01
影响因子：
2.3
通讯作者：
Pereira, Fabricio Jose
中科院分区：
文献类型：
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作者：
Pereira, Marcio Paulo;de Almeida Rodrigues, Luiz Carlos;Pereira, Fabricio Jose
低浓度的镉会引起叶子绿色组织的解剖学反应，从而增强红海龟的光合作用和耐受性。本工作旨在评估镉 (Cd) 对红海龟（一种能够应对恶劣环境的物种）叶子解剖结构和光合作用的影响。将 7 个月大的 S. molle 植物暴露于不同的 Cd 浓度（0、10、20、50、125 或 250 A muM，使用 Cd(NO3)(2) 作为 Cd 源）90 天以上。将植物放置在装有洗净的沙子和蛭石作为基质和营养液的花瓶中。在整个实验过程中，基质保持在田间持水量，并且每15天更换一次营养液。 90 天后，收集叶子并使用典型的植物显微技术进行解剖分析。此外，使用红外气体分析仪评估植物生长、光合作用、叶绿素含量和A/Ci曲线。 S.molle 的生长不受 Cd 的影响。较低的 Cd 浓度（10 和 20 A mu M）导致更大的净光合作用、气孔导度和密度、Vcmax、Jmax 和叶肉厚度。然而，50 A μM 或更高的 Cd 浓度导致大多数评估特性降低至接近对照的水平。所有测试的镉浓度都会导致叶绿素含量和气孔尺寸降低。因此，Cd 对诸如 S.molle 等耐受物种的影响是浓度依赖性的，在低 Cd 浓度下，这些植物可以通过调整叶子结构和功能来应对毒性。
Low concentrations of cadmium cause anatomical responses in leaf chlorenchyma enhancing Schinus molle photosynthesis and tolerance.This work is aimed to evaluate the effects of cadmium (Cd) on leaf anatomy and photosynthesis in Schinus molle, a species that can cope with harsh environments. Seven-month-old S. molle plants were exposed over 90 days to varying Cd concentrations (0, 10, 20, 50, 125 or 250 A mu M using Cd(NO3)(2) as the Cd source). The plants were placed in vases containing washed sand and vermiculite as the substrate and nutrient solution. Throughout the experiment, the substrate was maintained at field capacity, and the nutrient solution was replaced at 15-day intervals. After 90 days, leaves were collected and processed for anatomical analysis using typical plant microtechniques. In addition, plant growth, photosynthesis, chlorophyll content and A/Ci curve were evaluated using an infrared gas analyzer. S. molle growth was not affected by Cd. Lower Cd concentrations (10 and 20 A mu M) resulted in greater net photosynthesis, stomatal conductance and density, Vcmax, Jmax and mesophyll thickness. However, Cd concentrations of 50 A mu M or greater resulted in a reduction of most of the evaluated characteristics to levels close to control. All of the tested Cd concentrations resulted in reduced chlorophyll content and stomatal size. Therefore, the effect of Cd in a tolerant species such as S. molle is concentration dependent, and at low Cd concentrations, these plants can cope with the toxicity by adjusting leaf structure and function.