High Photosynthetic Rates in a Solanum pennellii Chromosome 2 QTL Is Explained by Biochemical and Photochemical Changes

Abstract

Enhanced photosynthesis is strictly associated with to productivity and it can be accomplished by genetic approaches through identification of genetic variation. By using a Solanum pennellii introgression lines (ILs) population, it was previously verified that, under normal (CO 2), IL 2-5 and 2-6 display increased photosynthetic rates by up to 20% in comparison with their parental background (M82). However, the physiological mechanisms involved in the enhanced CO 2 assimilation exhibited by these lines remained unknown, precluding their use for further biotechnological applications. Thereby, here we attempted to uncover the physiological factors involved in the upregulation of photosynthesis in ILs 2-5 and 2-6 under normal (CO 2) as well as under elevated (CO 2). The results provide evidence for increased biochemical capacity (higher maximum carboxylation velocity and maximum electron transport rate) in plants from IL 2-5 and 2-6, whereas the diffusive components (stomatal and mesophyll conductances) were unaltered in these ILs in comparison to M82. Our analyses revealed that the higher photosynthetic rate observed in these ILs was associated with higher levels of starch as well as total protein levels, specially increased RuBisCO content. Further analyses performed in plants under high (CO 2) confirmed that biochemical properties are involved in genetic variation on chromosome 2 related to enhanced photosynthesis.

Selection for drought tolerance in backcross populations derived from interspecific crosses of Solanum lycopersicum × Solanum pennellii

“…However, four of the BC 1 F 2 industrial processing and four of the fresh consumption progenies maintained A equal to their wild parent and higher to their commercial parents under drought, indicating a great tolerance potential on these progenies. In fact, introgression lines obtained from crossings between other commercial S. lycopersicum genotypes with S. pennellii have been also related to increased photosynthesis (Lana-Costa et al, 2020). Furthermore, stomatal closure is one of the first responses of tomatoes to drought, resulting in lower transpiration and CO 2 uptake and consequently, reducing photosynthesis (Hasanagi c et al, 2020).…”

Feeding the world: impacts of elevated [CO2] on nutrient content of greenhouse grown fruit crops and options for future yield gains

“…This work in wheat and rice is promising, demonstrating the potential for breeding new varieties better adapted to changing growth conditions, however it is unclear if such strategies will work in horticultural crops. In the case of tomato, there is considerable variation within the wild and elite varieties to suggest that such breeding strategies could be used to enhanced yield and quality [ 109 , 110 ]. See Sharwood et al [ 111 ] for review ( Figure 3 ).…”