Unidad de Recursos Naturales, Centro de Investigación Científica de Yucatán, C.P. 97205, Mérida, Yucatán, Mexico.
Campo Experimental Edzná, Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Km. 15.5 Carretera Campeche-Pocyaxum, C.P. 24520, Campeche, Mexico.
Physiol Plant. 2020 Mar;168(3):547-562. doi: 10.1111/ppl.12805. Epub 2018 Sep 25.
Climate change is expected to increase the frequency of extreme climatic events, yet few studies have addressed the capacity of plant species to deal with such events. Species that are widespread are predicted to be highly plastic and able to acclimate to highly changing conditions. To study the plasticity in physiological responses of the widely distributed epiphyte Tillandsia utriculata, we transplanted individuals from a coastal scrub and broadleaf evergreen forest to a similar coastal scrub site and forest. After a 45-day acclimation, the plants were moved to a semi-controlled greenhouse at each site, and then subjected to a 20-day drought. Physiological variables were measured during the acclimation and the drought. The individuals of scrub and forest populations had similar relative water content and carbon assimilation in the contrasting conditions of the two transplantation sites despite the high discrepancy between the environments at their original site. Electron transport rates were higher in individuals from the scrub population. Electron transport rates were also higher than estimated from carbon assimilation, suggesting that photorespiration was present. The individuals of the coastal scrub population had a higher capacity to dissipate excess energy this way. The relative distance index of plasticity was high overall, indicating that some traits are highly plastic (titratable acidity, carbon assimilation) in order to maintain the stability of others (maximum quantum yield F /F and relative water content). We conclude that T. utriculata is a highly plastic species with a high capacity to tolerate extreme environmental changes over a short time.
气候变化预计会增加极端气候事件的频率，但很少有研究探讨植物物种应对此类事件的能力。预计分布广泛的物种具有高度的可塑性，能够适应高度变化的条件。为了研究广泛分布的附生植物 Tillandsia utriculata 在生理响应方面的可塑性，我们将个体从沿海灌木丛和阔叶常绿林移植到类似的沿海灌木丛和森林中。经过 45 天的适应期后，将植物移至每个地点的半受控温室中，然后进行 20 天的干旱处理。在适应期和干旱期测量了生理变量。尽管原始地点的环境差异很大，但灌木丛和森林种群的个体在两个移植地点的对比条件下具有相似的相对水分含量和碳同化。来自灌木丛种群的个体的电子传递速率较高。电子传递速率也高于从碳同化估计的值，表明存在光呼吸。沿海灌木丛种群的个体具有更高的能力以这种方式耗散多余的能量。整体来看，相对距离可塑性指数较高，表明某些特征（可滴定酸度、碳同化）高度可塑性，以维持其他特征（最大量子产量 F/F 和相对水分含量）的稳定性。我们得出结论，T. utriculata 是一种高度可塑性的物种，能够在短时间内耐受极端环境变化。
