Genotypic difference in secondary metabolism‐related enzyme activities and their relative gene expression patterns, osmolyte and plant hormones in wheat

Abstract

Salinity and drought are the two most important and frequently co-occurring abiotic factors. A greenhouse pot experiment was carried out on two contrasting wheat genotypes (Jimai22, salt tolerant; Yangmai20, salt sensitive) to analyze the effect of drought (4% soil moisture content, D) and salinity (100 mM NaCl, S) either individually or combined on secondary metabolism-related enzyme activities and osmolytes. Results showed that drought, salinity and their combination (D + S) caused increases in phenylalanine ammonialyase (PAL, EC 4.3.1.24) activities compared with controls with a greater enhancement in Jimai22 than Yangmai20. Polyphenol peroxidase (PPO, EC 1.14.18.1) and shikimate dehydrogenase (SKDH, EC 1.1.1.25) activities increased more in Jimai22 both under salinity alone and D + S stresses. The D + S combination increased cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195) activity and glycine betaine (GB) under both 10 and 4% soil moisture contents (SMC), and elevated abscisic acid (ABA), indole-3-acetic acid (IAA) and flavonoid contents at 4% SMC in Jimai22, contents of the compounds remained unchanged in Yangmai20. The treatment with salinity alone at both SMCs significantly increased callose and flavonoid contents in Jimai22 more than in Yangmai20, as compared to controls. In addition, the total phenol content at 4% SMC increased in the salt-tolerant genotype more. Moreover, total tocopherol under salinity alone and D + S at 4% SMC and chitinase activity under salinity at both SMC remarkably increased in Jimai22 while non-significant change observed in Yangmai20. Also, the expression of genes related to secondary metabolism (PAL, PPO, CAD, SKDH, and GB) was more induced in Jimai22 than Yangmai20 under D + S, and lower accumulation of H 2 O 2 and O 2 − also occurred. Our findings suggest that high tolerance to D + S stress in Jimai22 was closely related to enhanced secondary metabolism-related enzyme activities and osmolytes such as PAL, CAD, PPO, SKDH, GB, total tocopherol, callose, plant hormones and their transcript level, which may beneficial to lower the reactive oxygen species (ROS) accumulation.

Resemblance and Difference of Seedling Metabolic and Transporter Gene Expression in High Tolerance Wheat and Barley Cultivars in Response to Salinity Stress

“…In this study, the highest increase of activity of SKDH under saline stress in the roots and leaves was detected in CM72, but the increase in wheat cultivars was very small. Consistent with this finding, Ahmad et al (2015) [37] reported a boosted SKDH enzyme activity in barley genotypes and Tesfaye et al (2019) [38] in wheat genotypes under combined stress of drought and salinity.…”

Integrated transcriptomic and metabolomic analyses revealed the molecular mechanism of terpenoid formation for salicylic acid resistance in Pulsatilla chinensis callus

“…The formation and accumulation of secondary metabolites in medicinal plants are regulated by a variety of factors. In recent years, environmental factors, hormone regulation, and the expression and regulation of functional genes had often been reported (Martins et al, 2018;Ibrahim et al, 2019;Dugasa et al, 2020). The early results showed that the growth period of suspension culture callus was about 40 days: the slow growth period was 0-9 days; the exponential growth period was 12-24 days; the platform period is 27-39d; the decline period was 39 days after culture (Supplementary Figure 7).…”

Effect of Polyethylene Glycol-Simulated Drought Stress on Stomatal Opening in “Modern” and “Ancient” Wheat Varieties

“…Increased drought has a significant impact on plant growth and development, resulting in a notable decline in cereal yields, including durum wheat ( Triticum turgidum ssp. durum ), which is one of the most important cereal crops grown worldwide [ 5 ]. In this framework, the rediscovery of ancient varieties with their wide genetic diversity is a promising strategy to improve wheat fitness in light of climate change.…”