High Night Temperature and Abscisic Acid Affect Rice Productivity through Altered Photosynthesis, Respiration and Spikelet Fertility

Abstract

High night temperature (HNT) is among the important abiotic stresses limiting rice production. The impacts of abscisic acid (ABA) on higher plants have been the subject of many studies. However, little or no work has been performed on rice responses to ABA under HNT‐stress conditions. This study determined the effects of ABA on rice leaf photosynthetic rate (PN), photochemistry, respiration, and physiology under HNT. Plants were grown under ambient night temperature (ANT; 25°C) or HNT (30°C) with or without ABA (100 ppm) application from the boot stage of rice plants until harvest. The HNT decreased rice yield (11%), which was associated with decreasing PN (5%), pollen viability (11%), and spikelet fertility (5%) and increasing respiration rate (44%). In addition, HNT decreased grain width (4%) and increased grain chalkiness (65%), thereby decreasing grain quality. The ABA‐treated plants showed increased yield (15%) as a result of increased PN (6%) and spikelet fertility (6%) and decreased respiration (33%), under HNT. The increased PN under HNT as a result of ABA application is associated with increased stomatal conductance (22%) and decreased nonphotochemical quenching (NPQ; 29%). In addition, ABA‐treated plants grown under ANT also showed increased yield (9%) as a result of increased PN (7%) and spikelet fertility (7%) and decreased respiration (16%). The increased PN under ANT as a result of ABA application was due to increased quantum yield (8%) and electron transport rate (8%). This study shows that exogenous application of ABA has the potential to increase rice yields under HNT.

The Effects of Night-time Temperatures on Physiological and Biochemical Traits in Rice

“…1). The adverse effects of HNT on leaf photosynthesis also has been reported in rice (Mohammed et al, 2013) and sorghum (Prasad and Djanaguiraman, 2011). The decrease in Pn under HNT can be associated with a reduction in stomatal conductance (Mohammed et al, 2013) and alterations in plant carbohydrate content because of the lower hexose and sucrose concentrations in heat-stressed leaves (Loka and Oosterhuis, 2016).…”

“…However, the ʻLV1401ʼ genotype seedlings had the highest specific leaf area. In general, a lower plant biomass in rice plants subjected to 30°C could be due to a balance between photosynthesis and night respiration in rice plants (Cheng et al, 2009;Mohammed et al, 2013). HNT causes a lower photosynthetic rate and increased respiration, and it can adversely affect membrane stability, causing a lower biomass accumulation (Peng et al, 2004).…”

Plant Physiological, Morphological and Yield-Related Responses to Night Temperature Changes across Different Species and Plant Functional Types

“…There was a consistent suppression on A net (net CO 2 assimilation rate) at LNT for both C 3 (Flexas and Osmond, 1999; Bange and Milroy, 2004; Zhang et al, 2010; Sao et al, 2013b) and C 4 species (Sao et al, 2013a), but a stimulation for CAM species (Chen et al, 2008; Pollet et al, 2011). HNT had a positive (Seddigh and Jolliff, 1984c; Prieto et al, 2009; Darnell et al, 2013), negative (Teragishi et al, 2001; Mohammed et al, 2013; Narayanan et al, 2015; Peraudeau et al, 2015), or no effect (Veatch et al, 2007; Ibrahim et al, 2010; Cheesman and Klaus, 2013) on A net for C 3 species and a negative (Prasad and Djanaguiraman, 2011) effect for C 4 species. The effect of HNT and LNT on photosynthesis was related to leaf chlorophyll content (Prasad and Djanaguiraman, 2011), fluorescence parameters including photochemical efficiency of PSII ( F v / F m ), PSII quantum yield (Φ PSII ) and ETR (Liu et al, 2011, 2012; Zhang et al, 2014), nitrogen (N) concentration (Mohammed and Tarpley, 2009a), g s (stomatal conductance) (Farquhar and Sharkey, 1982) and enzyme activities related to carbon fixation (Noctor and Foyer, 1998).…”

“…In fact, the effects of night temperature are different from that of day temperature (Xia et al, 2014) and produced a relatively greater challenge in estimating global change impact on crop yield and ecosystem functions (Jagadish et al, 2015). Previous studies on night temperatures have focused either on the effects of HNT and LNT alone (Friend, 1981; Seddigh and Jolliff, 1984a,b,c; Koscielniak, 1993; Bertamini et al, 2005) or the mixed effects of night temperatures and CO 2 concentration (Mortensen and Moe, 1992; Volder et al, 2004; Cheng et al, 2008, 2009, 2010), light period (Gimenez and Rumi, 1988; Turner and Ewing, 1988; Lee et al, 1991; Verheul et al, 2007), intensity (Bunce, 1985; Mortensen, 1994; Rapacz, 1998; Flexas and Osmond, 1999; Davies et al, 2002) as well as other environmental factors (Schoppach and Sadok, 2013) and growth regulators (Shah et al, 2011; Mohammed et al, 2013; Zhang et al, 2014). These experiments had been conducted on pineapple (Neales et al, 1980), peanut (Bagnall et al, 1988; Wang, 2007; Lin et al, 2011) and shrub-grass ecosystems (Beier et al, 2004).…”

Temporal chlorophyll fluorescence signals to track changes in optical properties of maturing rice panicles exposed to high night temperature

“…on rice yield has been confirmed by controlled-environment studies (Kanno and Makino, 2010;Mohammed and Tarpley, 2009, 2011Mohammed et al, 2013) and recently from field experiments . Interestingly, under field conditions, the major cause of reduced yield under HNT was due to the overall reduction in biomass and non-structural carbohydrate (NSC) content, particularly in the panicles .…”