Increased Rubisco content in maize mitigates chilling stress and speeds recovery

Abstract

Many C 4 plants, including maize, perform poorly under chilling conditions. This phenomenon has been linked in part to decreased Rubisco abundance at lower temperatures. An exception to this is chilling-tolerant Miscanthus, which is able to maintain Rubisco protein content under such conditions. The goal of this study was to investigate whether increasing Rubisco content in maize could improve performance during or following chilling stress. Here, we demonstrate that transgenic lines overexpressing Rubisco large and small subunits and the Rubisco assembly factor RAF1 (RAF1-LSSS), which have increased Rubisco content and growth under control conditions, maintain increased Rubisco content and growth during chilling stress. RAF1-LSSS plants exhibited 12% higher CO 2 assimilation relative to nontransgenic controls under control growth conditions, and a 17% differential after 2 weeks of chilling stress, although assimilation rates of all genotypes were~50% lower in chilling conditions. Chlorophyll fluorescence measurements showed RAF1-LSSS and WT plants had similar rates of photochemical quenching during chilling, suggesting Rubisco may not be the primary limiting factor that leads to poor performance in maize under chilling conditions. In contrast, RAF1-LSSS had improved photochemical quenching before and after chilling stress, suggesting that increased Rubisco may help plants recover faster from chilling conditions. Relatively increased leaf area, dry weight and plant height observed before chilling in RAF1-LSSS were also maintained during chilling. Together, these results demonstrate that an increase in Rubisco content allows maize plants to better cope with chilling stress and also improves their subsequent recovery, yet additional modifications are required to engineer chilling tolerance in maize.

Effects of the Chloroplast Fructose-1,6-Bisphosphate Aldolase Gene on Growth and Low-Temperature Tolerance of Tomato

“…However, since the 1990s, studies have found that reductions in the activity of Rubisco have little impact on carbon assimilation under normal environmental conditions [ 32 , 33 , 34 ]. Rubisco may not be the primary limiting factor that leads to poor performance under chilling conditions but instead helps plants recover faster from these conditions [ 35 ]. Recent studies have shown that there is a non-regulated enzyme, aldolase, that is sensitive to abiotic stresses [ 36 , 37 , 38 ].…”

Adaptation of Temperate Seagrass to Arctic Light Relies on Seasonal Acclimatization of Carbon Capture and Metabolism

“…The presence of this activator, which removes the RuBisCO inhibitor CAP (2-carboxylarabinitol-1,5-bisphosphate), suggests that the Norwegian population could indeed maintain carbon fixation during the dark winter period. If increased RuBisCO expression in Norwegian winter samples is related to cold-acclimation, as shown in maize (Salesse-Smith et al, 2020), then warmer winters could hinder carbon assimilation and, thus, survival in the future Arctic.…”

Exogenous Ca2+ priming can improve peanut photosynthetic carbon fixation and pod yield under early sowing scenarios in the field

“…Thus, it is paramount for peanut growers and researchers to uncover suitable sowing windows and cultivation durations in high-latitude areas to deliver successful peanut production ( Dai et al., 2017 ; Li et al., 2018 ; Virk et al., 2020 ; Zhang et al., 2020 ). For the cropping boundary in the high-latitude crop, especially in response to low-temperature stress, the peanut’s light interception and strong sink demand are the major determinants of high yield and quality ( Bagnall et al., 1988 ; Itoh, 2003 ; Salessesmith et al., 2020 ; Ensminger et al., 2006 ). However, the ES (early sowing) window in the most high-latitude area would naturally subject the crop to a greater probability of chilling exposure.…”