Department of Environment Studies, Panjab University, Chandigarh, 160 014, India.
Department of Botany, Panjab University, Chandigarh, India.
Environ Monit Assess. 2021 Nov 2;193(11):762. doi: 10.1007/s10661-021-09504-1.
Plant species exhibiting heavy metal tolerance are instrumental in phytoremediation of metalliferous sites. Most of the time, variations in plant functional traits (PFTs) are overlooked while identifying hyperaccumulators. However, investigating morphological, physiological, and phenological variations can contribute to our knowledge about stress tolerance, and aid in identifying potential hyperaccumulators. In the present study, we investigated variation in morpho-functional traits in Solanum nigrum, a known hyperaccumulator, under lead (Pb) stress. Twenty-one PFTs including 9 above-ground (leaf count, leaf area, specific leaf area, leaf dry matter content, leaf thickness, leaf dry mass, shoot length, stem dry mass, stem diameter), 3 below-ground (root length, root dry mass, and root diameter), 4 reproductive (flower bud count, fruit count, flower count, and fruit dry mass), and 5 photosynthetic traits (total chlorophyll, total carotenoid, chlorophyll a, chlorophyll b, and photosynthetic efficiency) under varying Pb concentrations (500-2000 mg kg) were assessed. Pillai's trace test (MANOVA) depicted significant variations in above-ground, below-ground, and photosynthetic traits, whereas reproductive traits did not vary significantly with progressive metal concentration. However, most of the studied traits except flower count, fruit dry mass, and chlorophyll b varied significantly under Pb stress. The study depicts that enhanced PFT's plasticity enables S. nigrum to grow in Pb-contaminated soil effectively without impacting plant fitness. Plasticity of morpho-functional traits, therefore, establishes itself as a resourceful approach in successful identification of phytoremediation capacity of a plant.
具有重金属耐受能力的植物物种在金属污染场地的植物修复中起着重要作用。在识别超富集植物时，大多数情况下会忽略植物功能性状（PFT）的变化。然而，研究形态、生理和物候变化可以帮助我们了解植物的耐胁迫能力，并有助于识别潜在的超富集植物。在本研究中，我们研究了已知超富集植物龙葵（Solanum nigrum）在铅（Pb）胁迫下的形态功能性状变化。21 种 PFT 包括 9 种地上部分（叶数、叶面积、比叶面积、叶干物质含量、叶厚度、叶干重、茎长、茎干重、茎直径），3 种地下部分（根长、根干重和根直径），4 种生殖部分（花蕾数、果实数、花数和果实干重）和 5 种光合特性（总叶绿素、总类胡萝卜素、叶绿素 a、叶绿素 b 和光合效率），在不同的 Pb 浓度（500-2000mgkg）下进行评估。Pillai 的迹检验（MANOVA）显示，地上部分、地下部分和光合特性有显著变化，而生殖特性随金属浓度的增加没有显著变化。然而，除了花数、果实干重和叶绿素 b 外，大多数研究性状在 Pb 胁迫下变化显著。研究表明，增强的 PFT 可塑性使龙葵能够有效地在 Pb 污染的土壤中生长，而不会影响植物的适应性。因此，形态功能性状的可塑性是成功识别植物修复能力的一种富有成效的方法。
