Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings

Abstract

Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans’ attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants.

Airborne signals synchronize the defenses of neighboring plants in response to touch

“…Expression of genes for mitogen-activated kinases such as MKK1 has also been shown to be triggered by ROS and antioxidants in maize and to affect the plants’ innate immunity (Zhang et al , 2006; Gao et al , 2008). Maize plants trigger expression of early defense genes such as superoxide distmutase ( SOD ) and APX in response to aphid attack (Sytykiewicz, 2014, 2016). In addition, we also measured transcript abundance of defense genes whose products are known to affect insect performance directly, such as proteinase inhibitors and benzoxazinoids.…”

The manipulation of gene expression and the biosynthesis of Vitamin C, E and folate in light-and dark-germination of sweet corn seeds

“…Three key genes ( VTC2 , GLDH , DHAR ) affect the biosynthetic pathway of vitamin C 4, 17, 18 , the expression levels of these genes were studied and the results presented in Fig. 4.…”

Hydrogen Peroxide Response in Leaves of Poplar (Populus simonii × Populus nigra) Revealed from Physiological and Proteomic Analyses

“…MDHAR and DHAR catalyze the regeneration of AsA, using nicotinamide adenine dinucleotide phosphate (NADPH) and GSH as electron source/donor, respectively, while GR maintains the cellular reduced GSH pool through converting GSSG to GSH with NADPH. The stress-induced activities of DHAR and GR also have been reported in several plants (e.g., maize and pepper) in response to abiotic stresses, such as salinity, drought, low temperature, and heavy metal [ 46 ]. This suggests that the H 2 O 2 -induced activities of DHAR and GR would maintain the reduced AsA and GSH pools for antioxidative processes in leaves.…”