Single and Combined Salinity and Heat Stresses Impact Yield and Dead Pericarp Priming Activity

Abstract

In the face of climate change and the predicted increase in the frequency and severity of abiotic stresses (e.g., hot spell, salinity), we sought to investigate the effect of salinity (S), short episodes of high temperature (HS) and combination of salinity and high temperature (SHS), at the reproductive phase, on yield with a special focus on the properties of dead pericarps of Brassica juncea. Three interval exposures to HS resulted in massive seed abortion, and seeds from salt-treated plants germinated poorly. Germination rate and final germination of B. juncea seeds were slightly reduced in the presence of salt and SHS pericarp extracts. All pericarp extracts completely inhibited seed germination of tomato and Arabidopsis, but removal of pericarp extracts almost fully restored seed germination. Heat and salinity profoundly affected the accumulation of phytohormones in dead pericarps. Combined stresses highly reduced IAA and ABA levels compared with salt, and enhanced the accumulation of GA1, but abolished the positive effect of salt on the accumulation of GA4, JA and SA. Interestingly, pericarp extracts displayed priming activity and significantly affected seedling performance in a manner dependent on the species and on the origin of the pericarp. While control pericarps improved and reduced the seedlings’ performance of autologous and heterologous species, respectively, pericarps from salt-treated plants were harmless or improved heterologous seedling performance. Thus, the strategy employed by the germinating seed for securing resources is set up, at least partly, by the mother plant in conjunction with the maternal environment whose components are stored in the dead maternal organs enclosing the embryo.

What Worth the Garlic Peel

“…Interestingly, in contrast to the cloves, which strongly inhibited the growth of Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria, garlic peel extracts had a promotive effect on bacterial growth. Likewise, dead organs enclosing the embryo, such as dead pericarps of S. alba and B. juncea and the husk of Avena sterilis, were found to accumulate substances that significantly enhanced bacterial growth; pericarps of Anastatica hierochuntica possess substances that strongly inhibited microbial growth [6,8,13,35,36]. Indeed, garlic skin has been reported recently to affect bacterial communities.…”

Cereal Husks: Versatile Roles in Grain Quality and Seedling Performance

“…Indeed, DOEEs were found to accumulate substances that affect microbial growth in a species-dependent manner. Avena husks as well as S. alba and B. juncea pericarps contain substances that significantly enhance bacterial growth [3,24,67], while pericarps of the desert crucifer Anastatica hierochuntica contain substances that strongly inhibit microbial growth [68,69]. The differential effect of DOEEs on microbial growth may be related to the mode of interaction between plants and their distinct habitats, as well as the co-evolution with their specific microbiota.…”

Regenerative strategies of Euterpe edulis (Arecaceae) at its altitudinal limits in the Atlantic Forest

“…Microclimatic variations such as heat waves are becoming more frequent due to climate change (TT‐DEWCE WMO, 2023). Not all strategies used by plants to cope with stress are successful, and some symptoms, such as fruit weight reduction, seed abortion and reduced seed filling, may be observed (Martínez‐Lüscher et al., 2020; Swetha et al., 2021). Studies show that heat waves at temperatures of 37–45°C in the first 24 h are sufficient to generate deleterious effects on seeds (Martínez‐Lüscher et al., 2020; Swetha et al., 2021; Tokić et al., 2023).…”

“…Not all strategies used by plants to cope with stress are successful, and some symptoms, such as fruit weight reduction, seed abortion and reduced seed filling, may be observed (Martínez‐Lüscher et al., 2020; Swetha et al., 2021). Studies show that heat waves at temperatures of 37–45°C in the first 24 h are sufficient to generate deleterious effects on seeds (Martínez‐Lüscher et al., 2020; Swetha et al., 2021; Tokić et al., 2023). However, this condition may be related to the thermal tolerance of the species.…”