Programa de Pós-Graduação em Biologia Vegetal, Departamento de Biodiversidade, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Rio Claro, SP, Brazil.
Curso de graduação em Ciências Biológicas, Departamento de Biodiversidade, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Rio Claro, SP, Brazil.
Plant Biol (Stuttg). 2023 Aug;25(5):740-749. doi: 10.1111/plb.13535. Epub 2023 May 31.
Aluminium (Al) is toxic to most plants. Nevertheless, some species accumulate Al without showing toxicity symptoms. Previous studies have evidenced Al in chloroplasts of Al-accumulating species from the Cerrado vegetation in South America. We ask whether Al increases carbon assimilation through enhanced apparent efficiency of Rubisco. Seedlings of the Al-accumulator Qualea grandiflora (Vochysiaceae) were grown in nutrient solution with 0, 740, and 1480 μm Al. Growth parameters, relative leaf water content, Al concentration in organs, gas exchange and apparent carboxylation efficiency (measured from A/Ci curves) were evaluated for 60 days. Plants without Al showed no root growth, necrotic roots, low gas exchange rates, and decreased apparent carboxylation efficiency. Al-treated plants, however, showed new white roots and increased root biomass leading to higher leaf hydration, and apparent carboxylation efficiency was higher in these plants. Increased Al available in the nutrient solution increased Al accumulation in plant organs. Absence of Al compromised root integrity in Q. grandiflora, thus limiting leaf hydration. No positive direct effect of Al on Rubisco was evidenced in Al-treated plants.
铝（Al）对大多数植物都有毒。然而，一些物种在积累铝的同时没有表现出毒性症状。先前的研究表明，在来自南美的塞拉多植被的铝积累物种的叶绿体中存在铝。我们想知道铝是否通过增强 Rubisco 的表观效率来增加碳同化。在含有 0、740 和 1480 μm Al 的营养液中生长的铝积累植物 Qualea grandiflora（茜草科）幼苗，在 60 天内评估生长参数、相对叶片水分含量、器官中的 Al 浓度、气体交换和表观羧化效率（从 A/Ci 曲线测量）。没有 Al 的植物没有根生长，出现坏死根、低气体交换率和降低的表观羧化效率。然而，用 Al 处理的植物长出了新的白色根，根生物量增加，导致叶片水合作用更高，这些植物的表观羧化效率更高。营养液中可利用的 Al 增加，导致植物器官中 Al 积累增加。在 Q. grandiflora 中，缺乏 Al 会损害根的完整性，从而限制叶片水合作用。在 Al 处理的植物中没有发现 Al 对 Rubisco 的直接正向影响。
