Natural genetic variation in photosynthesis: an untapped resource to increase crop yield potential?

Abstract

Raising crop yield potential is a major goal to ensure food security for the growing global population. Photosynthesis is the primary determinant of crop productivity and any gain in photosynthetic CO 2 assimilation per unit of leaf area (A) has the potential to increase yield. Significant intraspecific variation in A is known to exist in various autotrophic organs that represent an unexploited target for crop improvement. However, the large number of factors that influence photosynthetic rates often makes it difficult to measure or estimate A under dynamic field conditions (i.e. fluctuating light intensities or temperatures). This complexity often results in photosynthetic capacity, rather than realized photosynthetic rates being used to assess natural variation in photosynthesis. Here we review the work on natural variation in A, the different factors determining A and their interaction in yield formation. A series of drawbacks and perspectives are presented for the most common analyses generally used to estimate A. The different yield components and their determination based on different photosynthetic organs are discussed with a major focus on potential exploitation of various traits for crop improvement. To conclude, an example of different possibilities to increase yield in wheat through enhancing A is illustrated. -Greenhouse conditions Ouyang et al. (2017) Rice 0.15-0.31 0.05-0.21 Pot experiment

Leaf Monoterpene Emission Limits Photosynthetic Downregulation under Heat Stress in Field-Grown Grapevine

“…Under high temperatures, an increase in g s and transpiration has been often observed for several species [ 32 ]. Indeed, as temperatures rise, the increase in evaporative cooling associated with higher g s can maintain leaf temperature to optimal levels for photosynthesis [ 33 , 34 ] or even prevent leaf temperatures from reaching a harmful threshold for leaf survival. In our work, g s was reduced under high leaf temperatures, potentially following an ABA-induced stomatal closure owing to an increase in leaf-to-air vapor pressure deficit [ 35 ].…”

The potential of dynamic physiological traits in young tomato plants to predict field-yield performance

“…Physiological traits (e.g. photosynthesis or stomatal conductance) are key contributors to plant productivity and yield (Roche, 2015; Faralli and Lawson, 2020). However, existing methods of measuring these traits are mostly manual and thus are limited to a single point on a single leaf at a time (Iseki and Olaleye, 2020).…”

“…Recent advances in crop physiology show that under drought conditions, quantitative physiological traits such as stomatal conductance (Bahar et al , 2009), osmotic adjustment, accumulation and remobilization of stem reserves and photosynthetic efficiency are strongly correlated with yield (Richards et al , 2002; Aisawi et al , 2015; Teodoro et al , 2019). Nevertheless, most of the available models do not include key plant physiological traits, such as g sc and photosynthesis, which contribute to crop productivity (Roche, 2015; Faralli and Lawson, 2020). These traits are among the primary and most sensitive responses of the plant to the changing environment (Pirasteh-Anosheh et al , 2016) and this dynamic behavior helps to optimize the plant’s response to changing environmental conditions and probably also helps to maximize yield.…”

Will Plant Genome Editing Play a Decisive Role in “Quantum-Leap” Improvements in Crop Yield to Feed an Increasing Global Human Population?

“…The successful modification of photosynthesis to enhance plant growth and yield has been limited to a few cases [88,89]. This provides some support that the genetic engineering approach is an avenue worth pursuing for the improvement in Yp through the optimisation of photosynthetic processes [18,80,81,90,91].…”