Season Affects Yield and Metabolic Profiles of Rice (Oryza sativa) under High Night Temperature Stress in the Field.

Stephanie Schaarschmidt,S V Krishna Jagadish,Xia Li,Ellen Zuther,Alexander Erban,Joachim Kopka,Dirk K Hincha,Lovely Mae F Lawas,Ulrike Glaubitz

doi:10.3390/ijms21093187

Abstract

Rice (Oryza sativa) is the main food source for more than 3.5 billion people in the world. Global climate change is having a strong negative effect on rice production. One of the climatic factors impacting rice yield is asymmetric warming, i.e., the stronger increase in nighttime as compared to daytime temperatures. Little is known of the metabolic responses of rice to high night temperature (HNT) in the field. Eight rice cultivars with contrasting HNT sensitivity were grown in the field during the wet (WS) and dry season (DS) in the Philippines. Plant height, 1000-grain weight and harvest index were influenced by HNT in both seasons, while total grain yield was only consistently reduced in the WS. Metabolite composition was analysed by gas chromatography-mass spectrometry (GC-MS). HNT effects were more pronounced in panicles than in flag leaves. A decreased abundance of sugar phosphates and sucrose, and a higher abundance of monosaccharides in panicles indicated impaired glycolysis and higher respiration-driven carbon losses in response to HNT in the WS. Higher amounts of alanine and cyano-alanine in panicles grown in the DS compared to in those grown in the WS point to an improved N-assimilation and more effective detoxification of cyanide, contributing to the smaller impact of HNT on grain yield in the DS.

Highlights

Rice is a staple food for more than half of the world’s population and the demand is steadily increasing with the growing human population [1]
The response of agronomic parameters and metabolic patterns to high night temperature” (HNT) have been analyzed for eight rice cultivars with different HNT tolerance under field conditions at the International Rice Research Institute (IRRI) in two different seasons
Temperature data for the two growth seasons largely agree between our study and two earlier reports for the same location [13,20], indicating that the plants in our study were exposed to normal climatic conditions without any extreme weather events

Summary

Introduction

Rice is a staple food for more than half of the world’s population and the demand is steadily increasing with the growing human population [1]. Climate change is a significant limiting factor for enhancing food production, because increasing abiotic and biotic stresses negatively affect the yield of all major crops [2,3,4]. The global surface temperature has increased by an average of 0.85 ◦C, and a further increase of up to 3.7 ◦C has been predicted by 2100 [3]. This temperature increase develops asymmetrically, with a faster rise in daily minimum compared to daily maximum temperatures [5,6,7,8,9], leading to “high night temperature” (HNT) conditions. The main rice-growing countries in Asia, including China [11], the Philippines [12,13] and India [14,15], are affected

Objectives

Methods

Results

Conclusion