Hydrogen Peroxide and GA3 Levels Regulate the High Night Temperature Response in Pistils of Wheat (Triticum aestivum L.)

Purbali Mukherjee; Pavithra Suriyakumar; S Vanchinathan; Veda Krishnan; Milan Kumar Lal; Prakash Kumar Jha; Viswanathan Chinnusamy; Anjali Anand; P V Vara Prasad

doi:10.3390/antiox12020342

Hydrogen Peroxide and GA₃ Levels Regulate the High Night Temperature Response in Pistils of Wheat (Triticum aestivum L.)

Antioxidants (Basel). 2023 Jan 31;12(2):342. doi: 10.3390/antiox12020342.

Authors

Purbali Mukherjee¹, Pavithra Suriyakumar¹, S Vanchinathan¹, Veda Krishnan², Milan Kumar Lal³, Prakash Kumar Jha⁴, Viswanathan Chinnusamy¹, Anjali Anand¹, P V Vara Prasad^{4

5}

Affiliations

¹ Division of Plant Physiology, Indian Council of Agricultural Research (ICAR)-Indian Agricultural Research Institute, New Delhi 110012, India.
² Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India.
³ Division of Crop Physiology, Biochemistry and Post-Harvest Technology, ICAR-Central Potato Research Institute, Shimla 171001, India.
⁴ Feed the Future Innovation Lab for Collaborative Research on Sustainable Intensification, Kansas State University, Manhattan, KS 66506, USA.
⁵ Department of Agronomy, Kansas State University, Manhattan, KS 66506, USA.

Abstract

High night temperature (HNT) impairs crop productivity through the reproductive failure of gametes (pollen and pistil). Though female gametophyte (pistil) is an equal partner in the seed-set, the knowledge of the antioxidant system(s) and hormonal control of HNT tolerance or susceptibility of pistils is limited and lacking. The objectives of this study were to determine the antioxidant mechanism for homeostatic control of free radicals, and the involvement of abscisic acid (ABA) and gibberellic acid (GA₃) in HNT stress protection in the wheat pistils of contrasting wheat genotypes. We hypothesized that HNT tolerance is attributed to the homeostatic control of reactive oxygen species (ROS) and hormonal readjustment in pistils of the tolerant genotype. The ears of two contrasting wheat genotypes-HD 2329 (susceptible) and Raj 3765 (tolerant) were subjected to two HNTs (+5 °C and +8 °C) over ambient, in the absence and presence of dimethylthiourea (DMTU), a chemical trap of hydrogen peroxide (H₂O₂). Results showed that HNTs significantly increased ROS in pistils of susceptible genotype HD 2329 to a relatively greater extent compared to tolerant genotype Raj 3765. The response was similar in the presence or absence of DMTU, but the H₂O₂ values were lower in the presence of DMTU. The ROS levels were balanced by increased activity of peroxidase under HNT to a greater extent in the tolerant genotype. Cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC) activity was inversely related to H₂O₂ production within a critical range in Raj 3765, indicating its modulation by H₂O₂ levels as no change was observed at the transcriptional level. The hormonal status showed increased ABA and decreased GA₃ contents with increasing temperature. Our study elucidates the role of H₂O₂ and GA₃ in stress tolerance of pistils of tolerant genotype where GAPC acts as a ROS sensor due to H₂O₂-mediated decrease in its activity.

Keywords: ABA; GA3; Glyceraldehyde-3-phosphate dehydrogenase; high night temperature; hydrogen peroxide; pistil; wheat.

Grants and funding

This research received no external funding.