Activities of leaf and spike carbohydrate-metabolic and antioxidant enzymes are linked with yield performance in three spring wheat genotypes grown under well-watered and drought conditions

Abstract

Background: To improve our understanding about the physiological mechanism of grain yield reduction at anthesis, three spring wheat genotypes [L 1 (advanced line), L 2 (Vorobey) and L 3 (Punjab-11)] having contrasting yield potential under drought in field were investigated under controlled greenhouse conditions, drought stress was imposed at anthesis stage by withholding irrigation until all plant available water was depleted, while wellwatered control plants were kept at 95% pot water holding capacity. Results: Compared to genotype L 1 and L 2 , pronounced decrease in grain number (NGS), grain yield (GY) and harvest index (HI) were found in genotype L 3 , mainly due to its greater kernel abortion (KA) under drought. A significant positive correlation of leaf monodehydroascorbate reductase (MDHAR) with both NGS and HI was observed. In contrast, significant negative correlations of glutathione S-transferase (GST) and vacuolar invertase (vacInv) both within source and sink were found with NGS and HI. Likewise, a significant negative correlation of leaf abscisic acid (ABA) with NGS was noticed. Moreover, leaf aldolase and cell wall peroxidase (cwPOX) activities were significantly and positively associated with thousand kernel weight (TKW). Conclusion: Distinct physiological markers correlating with yield traits and higher activity of leaf aldolase and cwPOX may be chosen as predictive biomarkers for higher TKW. Also, higher activity of MDHAR within the leaf can be selected as a predictive biomarker for higher NGS in wheat under drought. Whereas, lower activity of vacInv and GST both within leaf and spike can be selected as biomarkers for higher NGS and HI. The results highlighted the role of antioxidant and carbohydrate-metabolic enzymes in the modulation of source-sink balance in wheat crops, which could be used as bio-signatures for breeding and selection of drought-resilient wheat genotypes for a future drier climate.

Impact of elevated CO2 on two contrasting wheat genotypes exposed to intermediate drought stress at anthesis

“…The level of wheat phytohormones in leaves and spikes was examined further to understand the mechanism of yield reduction. We found an increase in ABA concentration under elevated CO 2 both in leaf and spike, and similar results were reported in recent studies (Shokat, Großkinsky, et al, 2020). In general, we measured an increase in the concentrations of most of the phytohormones under drought conditions for both ambient and elevated CO 2 and a negative correlation of ACC, I3A and most of the CKs with An, Gs and yield‐related traits were noticed.…”

“…Drought stress at anthesis interferes with normal floral development and lowers seed setting and grain filling in wheat and other crops (Ahmadi & Baker, 2001; Dong et al., 2017; Prasad, Pisipati, Momčilović, & Ristic, 2011; Razzaghi, Bahadori‐Ghasroldashti, Henriksen, Sepaskhah, & Jacobsen, 2020; Shokat, Großkinsky, Roitsch, & Liu, 2020; Shokat, Sehgal, Vikram, Liu, & Singh, 2020). Seed set is mainly reduced through lower water availability at meiosis causing malfunctioning of pollen grains (Dong et al., 2017; Westgate, Passioura, & Munns, 1996).…”

Genetic basis of some physiological traits and their association with yield in pre-breeding germplasm of bread wheat (Triticum aestivm L.)

“…As evident from Fig 1, Yd was very close to WUE confirming the results of correlation analysis. Previous reports indicate that higher Phr helps plants to maintain optimum grain yield as well as adaptability (Shokat et al, 2020b(Shokat et al, , 2021). In the current study, Phr was clustered closer to WUE and Yd (Fig.2) indicating maintenance of Yd could be due to higher WUE and Phr.…”

Comparative Analysis of the Glutathione S-Transferase Gene Family of Four Triticeae Species and Transcriptome Analysis of GST Genes in Common Wheat Responding to Salt Stress

“…Many GST genes have been reported to play central roles in protecting plants from abiotic and biotic stress [ 19 , 46 – 48 ]; therefore, they are potential targets for crop breeding and improvement.…”

“…Many GST genes have been reported to play central roles in protecting plants from abiotic and biotic stress [19,[46][47][48]; In this study, we identified a total of 346 GST genes in hexaploid common wheat (T. aestivum), 226 in tetraploid durum wheat (T. durum), 104 in diploid T. urartu, and 105 in diploid Ae. tauschii, using a comprehensive genomewide approach.…”