de Oliveira Raphael Ricon, Ribeiro Thales Henrique Cherubino, Cardon Carlos Henrique, Fedenia Lauren, Maia Vinicius Andrade, Barbosa Barbara Castanheira Ferrara, Caldeira Cecílio Frois, Klein Patricia E, Chalfun-Junior Antonio
Plant Physiology Sector, Biology Department, Universidade Federal de Lavras (UFLA), Lavras, Brazil.
Department of Horticultural Sciences, Texas A&M University, College Station, TX, United States.
Front Plant Sci. 2020 Jul 21;11:1113. doi: 10.3389/fpls.2020.01113. eCollection 2020.
The projected impact of global warming on coffee production may require the heat-adapted genotypes in the next decades. To identify cellular strategies in response to warmer temperatures, we compared the effect of elevated temperature on two commercial L. genotypes exploring leaf physiology, transcriptome, and carbohydrate/protein composition. Growth temperatures were 23/19°C (day/night), as optimal condition (OpT), and 30/26°C (day/night) as a possible warmer scenario (WaT). The cv. Acauã showed lower levels of leaf temperature (Tleaf) under both conditions compared to cv. Catuaí, whereas slightly or no differences for other leaf physiological parameters. Therefore, to explore temperature responsive pathways the leaf transcriptome was examined using RNAseq. Genotypes showed a marked number of differentially-expressed genes (DEGs) under OpT, however DEGs strongly decrease in both at WaT condition indicating a transcriptional constraint. DEGs responsive to WaT revealed shared and genotype-specific genes mostly related to carbohydrate metabolism. Under OpT, leaf starch content was greater in cv. Acauã and, as WaT temperature was imposed, the leaf soluble sugar did not change in contrast to cv. Catuaí, although the levels of leaf starch, sucrose, and leaf protein decreased in both genotypes. These findings revealed intraspecific differences in the underlying transcriptional and metabolic interconnected pathways responsive to warmer temperatures, which is potentially linked to thermotolerance, and thus may be useful as biomarkers in breeding for a changing climate.
全球变暖对咖啡生产的预计影响可能在未来几十年需要耐热基因型。为了确定应对温度升高的细胞策略，我们比较了高温对两种商业L.基因型的影响，研究了叶片生理学、转录组以及碳水化合物/蛋白质组成。生长温度为23/19°C（白天/夜晚）作为最佳条件（OpT），30/26°C（白天/夜晚）作为可能的升温情景（WaT）。与卡杜艾品种相比，阿考阿品种在两种条件下的叶片温度（Tleaf）水平较低，而其他叶片生理参数略有差异或无差异。因此，为了探索温度响应途径，使用RNAseq检测了叶片转录组。基因型在OpT条件下显示出大量差异表达基因（DEG），然而在WaT条件下，两个基因型中的DEG都大幅减少，表明存在转录限制。对WaT有响应的DEG揭示了主要与碳水化合物代谢相关的共享基因和基因型特异性基因。在OpT条件下，阿考阿品种的叶片淀粉含量更高，并且当施加WaT温度时，与卡杜艾品种相比，阿考阿品种的叶片可溶性糖没有变化，尽管两个基因型的叶片淀粉、蔗糖和叶片蛋白质水平都有所下降。这些发现揭示了种内对温度升高的潜在转录和代谢相互关联途径的差异，这可能与耐热性有关，因此可能作为应对气候变化育种中的生物标志物。
