Effects of heat shock and salinity on barley growth and stress-related gene transcription

Abstract

The effects of a short (30 min) heat shock (HS) on plants subsequently grown under a salinity stress (SS, 200 mM NaCl) for 10 d were investigated in barley (Hordeum vulgare L.) cv. Tokak 157/37. The maximum temperature for HS allowing plant survival was 45 °C. The root length was significantly decreased by SS, whereas HS alone did not affect root growth. Interestingly, HS stimulated root elongation under SS. An osmotic adjustment was promoted in leaves by SS. On the contrary, HS increased the osmotic potential in leaves in the absence of SS, and partly counteracted the effect of SS in the HS+SS treatment. Cu/Zn-SOD, HvAPX, HvCAT2, HSP17, HSP18, and HSP90 were transcribed in leaves of HS-treated plants, but not in control plants. The HSP70 was constitutively transcribed in both the SS and control plants, but after HS, a shorter amplicon was also observed. The genes coding antioxidants, Cu/Zn-SOD, HvCAT2 and HvAPX, were differentially influenced by SS or HS+SS in the roots and leaves. In the roots, the mRNA content of BAS1, HvDRF1, HvMT2, and HvNHX1 increased after the HS treatment. In a recovery experiment in which plants were grown to maturity after HS and HS+SS stress exposure, the plant height increased and the time to maturity was reduced in comparison with SS. Our results show that HS could stimulate plant growth and reduce some of the negative effects of SS, and that it affected the transcription of several stress-related genes.

Time‐course analysis of salicylic acid effects on ROS regulation and antioxidant defense in roots of hulled and hulless barley under combined stress of drought, heat and salinity

“…Various environmental stresses lead to reduction in individual growth parameters of plants. Barley root growth reduction with the stress of salinity (Shabala et al ), drought (Amini ) and heat (Faralli et al ) has been demonstrated separately in previous reports. The present study showed that the root length values significantly decreased, particularly after 72 h of the combined stress, and also that the reduction varied according to the barley cultivar type (hulled or hulless).…”

Rising CO2 from historical concentrations enhances the physiological performance of Brassica napus seedlings under optimal water supply but not under reduced water availability

“…On DAT 1, 4, 8 and 12, plants (n = 6) from each treatment were harvested for all the experiments. Relative water content (RWC) was calculated according to Barr & Weatherley (1962) and was determined as described by Faralli et al (2015). Briefly, between 1200 and 1300 h, one piece of leaf tissue of the fourth leaf (~2 cm 2 ) was collected using a scalpel for each plant (n = 6).…”

Mutations in the HvDWARF, HvCPD and HvBRI1 Genes-Involved in Brassinosteroid Biosynthesis/Signalling: Altered Photosynthetic Efficiency, Hormonal Homeostasis and Tolerance to High/Low Temperatures in Barley

“…High-temperature stress, in turn, is particularly dangerous to plants when it is combined with drought during the growing season. In the case of barley cultivars, the influence of high temperature on PSII efficiency Oukarroum et al 2016) and genes encoding antioxidant enzymes and heat shock proteins (Faralli et al 2015) was studied. At low temperature conditions the metabolic changes associated with cold adaptation and modifications of expression of the cold-regulated (COR) genes in barley cultivars were also investigated (Stanca et al 1996).…”