High-resolution shotgun proteomics reveals that increased air [CO2] amplifies the acclimation response of Coffea species to drought regarding antioxidative, energy, sugar, and lipid dynamics

Overexpression of Water-Responsive Genes Promoted by Elevated CO2 Reduces ROS and Enhances Drought Tolerance in Coffea Species

“…In comparison with CL153, Icatu showed (i) a higher number of expressed genes under MWD, but especially under SWD ( Figure 1 ); (ii) a higher number of specific DEGs, especially under SWD ( Figure 2 ); (iii) a higher number of DEGs involved in respiration, antioxidant activities, and lipid metabolism ( Figure 3 ); (iv) a higher activation of DEGs involved in light reactions of photosynthesis, the Calvin cycle and photorespiration ( Figure 4 ); and (v) a higher number of DEGs involved in responses to water deprivation and desiccation ( Figure 5 ). This transcriptional result explains previous physiological studies that reported a higher photochemical performance in Icatu than in CL153, due to the preservation or reinforcement of photosynthetic components, strengthened enzymatic antioxidative system, and a greater abundance of photoprotective pigments [ 7 , 12 , 26 , 27 ].…”

Protective Responses at the Biochemical and Molecular Level Differ between a Coffea arabica L. Hybrid and Its Parental Genotypes to Supra-Optimal Temperatures and Elevated Air [CO2]

“…These supported the maintenance of increased photosynthetic potential promoted by eCO 2 and the absence of photosynthesis down-regulation [ 35 ]. In fact, single eCO 2 promoted moderate responsiveness regarding the antioxidative response, which was much lower than the one felt under drought [ 78 ] or heat constraints [ 28 , 29 , 36 ] in those same C. canephora and C. arabica genotypes.…”

“…By contrast, only the eCO 2 plants of Marsellesa at 42/30 °C displayed a greater concentration of lutein (than their aCO 2 counterparts) which likely strengthened the thermal dissipation protection of photosystems against photooxidation in those plants. In fact, the eCO 2 positive impact on the performance of the photosynthetic apparatus and stress defenses was reported at physiological and molecular levels in studies involving other C. arabica and C. canephora genotypes, where a significant up-regulation of photosynthetic, antioxidant, and lipid metabolism genes and/or proteins was found under eCO 2 [ 28 , 29 , 35 ]. That ultimately mitigated the harsh effects of drought [ 27 , 28 , 29 ] and heat [ 34 , 36 ], supporting the maintenance of higher photosynthetic performance under eCO 2 in the studied coffee genotypes.…”

“…Furthermore, previous studies in Coffea spp. showed that the HSP70 protein synthesis is among the earlier responses to high temperatures [ 33 ], but also to moderate and severe drought, its presence further amplified under the superimposition with eCO 2 [ 29 ]. In the present study, a lower HSP70 expression under eCO 2 might also point to a lower need for stress protection and enhanced thermotolerance in these coffee plants since the up-regulation of HSP70 genes and the greater presence of this protein are usually found under stress conditions [ 36 , 95 ].…”

“…Therefore, the reinforcement of mechanisms dedicated to preventing ROS overproduction and/or its efficient scavenging is usually crucial to plant tolerance to a wide number of environmental constraints. That is also the case in Coffea spp., which shows a common antioxidative response to several stresses, such as drought [ 26 , 27 , 28 , 29 ], high irradiance [ 30 ], cold [ 24 , 31 , 32 ], and heat [ 33 , 34 , 35 , 36 ].…”