Distinct Cold Acclimation of Productivity Traits in Arabidopsis thaliana Ecotypes

Abstract

Improvement of crop climate resilience will require an understanding of whole-plant adaptation to specific local environments. This review places features of plant form and function related to photosynthetic productivity, as well as associated gene-expression patterns, into the context of the adaptation of Arabidopsis thaliana ecotypes to local environments with different climates in Sweden and Italy. The growth of plants under common cool conditions resulted in a proportionally greater emphasis on the maintenance of photosynthetic activity in the Swedish ecotype. This is compared to a greater emphasis on downregulation of light-harvesting antenna size and upregulation of a host of antioxidant enzymes in the Italian ecotype under these conditions. This differential response is discussed in the context of the climatic patterns of the ecotypes’ native habitats with substantial opportunity for photosynthetic productivity under mild temperatures in Italy but not in Sweden. The Swedish ecotype’s response is likened to pushing forward at full speed with productivity under low temperature versus the Italian ecotype’s response of staying safe from harm (maintaining redox homeostasis) while letting productivity decline when temperatures are transiently cold. It is concluded that either strategy can offer directions for the development of climate-resilient crops for specific locations of cultivation.

Genetic adaptations in the population history of Arabidopsis thaliana

“…The Swedish ecotype has extended its life cycle with earlier seedling establishment (early September) and late seed maturation (late June). As a result, it experiences similar temperatures to the Italian ecotype at corresponding developmental stages (Demmig-Adams et al, 2022).…”

Foliar Phenotypic Plasticity Reflects Adaptation to Environmental Variability

“…However, leaves grown under extremes of temperature or PFD did exhibit clear differences in the degree of plasticity of the characterized traits. Although outside the scope of this study, underlying genotypic differences among the three ecotypes involve the C-repeat binding factor (CBF) transcription factor family and its target genes as well as other regulators [ 31 , 33 , 56 ]. Considerable attention in studies of the ecotypic pair from Sweden and Italy has been paid to differences in freezing tolerance [ 29 , 30 , 31 , 32 , 33 ].…”

“…In contrast, the less pronounced upregulation of maximal photosynthetic capacity and foliar sugar-export capacity in the Italian ecotype was associated with a more pronounced adjustment of various processes that prevent oxidative damage from excess excitation energy when the utilization of absorbed light through photosynthesis is diminished. In particular, the Italian ecotype downregulated genes of light-harvesting complexes more than the Swedish ecotype under cold temperatures and high light [ 56 ], which apparently helped diminish excitation pressure [ 33 ]. In addition, the Italian ecotype upregulated multiple antioxidation processes that counteract oxidative stress more strongly than the Swedish ecotype [ 56 ].…”

“…In particular, the Italian ecotype downregulated genes of light-harvesting complexes more than the Swedish ecotype under cold temperatures and high light [ 56 ], which apparently helped diminish excitation pressure [ 33 ]. In addition, the Italian ecotype upregulated multiple antioxidation processes that counteract oxidative stress more strongly than the Swedish ecotype [ 56 ]. These responses may allow the Italian ecotype to persist throughout periods of cold temperature in a state well protected against oxidative stress despite diminished photosynthetic productivity.…”