Abstract
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 Coffea arabica 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.
Highlights
Climate change is multifaceted and despite measurable impacts of elevated temperatures on agriculture (Lobell et al, 2011; Zhao et al, 2017), there remains considerable gaps on how coffee systems will be affected by both short- and long-term changes in the environment
Present similar trends under optimal condition (OpT) and in response to warm temperatures (WaT), quantitative and transient differences were observed for the two genotypes during the 4-week experiment (Figure 1 and Table S1 for statistical analyses)
We found additional molecular pathways represented by differentially-expressed genes (DEGs) in response to warmer temperatures that included plant hormone signal transduction and carbon metabolism (Figures S5 and S6), represented, respectively, by the DEGs ABA RESPONSIVE ELEMENT BINDING FACTOR (ABF; Cc10_g04070) and PYRUVATE PHOSPHATE DIKINASE (PPDK; Cc03_g02730; EC:2.7.9.1)
Summary
Climate change is multifaceted and despite measurable impacts of elevated temperatures on agriculture (Lobell et al, 2011; Zhao et al, 2017), there remains considerable gaps on how coffee systems will be affected by both short- and long-term changes in the environment. Several studies on the impact of climate change on coffee systems have projected marked negative effects on yield, berry quality, suitable planting areas, and incidence of disease and insects (reviewed by DaMatta et al, 2019). These environmental stresses will likely impose both economic and social problems within many coffee producing regions (Bunn et al, 2014; Bunn et al, 2015). Mean temperatures are projected to increase by 2.6–4.8°C (IPCC, 2013; IPCC, 2014), which may have serious repercussions on coffee production Considering these changing temperatures, select genotypes were identified that outperformed others when exposed to higher annual mean temperatures (Damatta et al, 2018; Marie et al, 2020). This suggests there is potentially useful intraspecific variability of thermotolerance in some genotypes and investigation into the molecular mechanisms underlying this variability is warranted (DaMatta, 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
