Increased nighttime respiratory losses decrease the amount of photoassimilates available for plant growth and yield. We hypothesized that the increased respiratory carbon loss under high night temperatures(HNT) could ...Increased nighttime respiratory losses decrease the amount of photoassimilates available for plant growth and yield. We hypothesized that the increased respiratory carbon loss under high night temperatures(HNT) could be compensated for by increased photosynthesis during the day following HNT exposure. Two rice genotypes, Vandana(HNT-sensitive) and Nagina 22(HNT-tolerant), were exposed to HNT(4 ℃ above the control) from flowering to physiological maturity. They were assessed for alterations in the carbon balance of the source(flag leaf) and its subsequent impact on grain filling dynamics and the quality of spatially differentiated sinks(superior and inferior spikelets). Both genotypes exhibited significantly higher night respiration rates. However, only Nagina 22 compensated for the high respiration rates with an increased photosynthetic rate, resulting in a steady production of total dry matter under HNT. Nagina 22 also recorded a higher grain-filling rate, particularly at 5 and 10 d after flowering, with 1.5- and 4.0-fold increases in the translocation of ^(14)C sugars to the superior and inferior spikelets, respectively. The ratio of photosynthetic rate to respiratory rate on a leaf area basis was negatively correlated with spikelet sterility, resulting in a higher filled spikelet number and grain weight per plant, particularly for inferior grains in Nagina 22. Grain quality parameters such as head rice recovery, high-density grains, and gelatinization temperature were maintained in Nagina 22. An increase in the rheological properties of rice flour starch in Nagina 22 under HNT indicated the stability of starch and its ability to reorganize during the cooling process of product formation. Thus, our study showed that sink adjustments between superior and inferior spikelets favored the growth of inferior spikelets, which helped to offset the reduction in grain weight under HNT in the tolerant genotype Nagina 22.展开更多
The bioactive compounds in a food matrix can exist either in their free form or bound to other endogenous compounds,which may affect their bioactivities.This study investigated the impact of endogenous proteins and li...The bioactive compounds in a food matrix can exist either in their free form or bound to other endogenous compounds,which may affect their bioactivities.This study investigated the impact of endogenous proteins and lipids on the phenolics profile,anti-nephrolithiasis,and antioxidant activities of Monodora myristica(African nutmeg)seed.Endogenous proteins and lipids in M.myristica seed flour were removed by deproteinization and defatting,to obtain the deproteinized,defatted,and deproteinized-defatted flours.The native flour served as a control.Phenolics compounds in the flours were quantified using HPLC-DAD,while nephrolithiasis-associated enzymes(xanthine oxidase and urease)inhibitory and antioxidant activities were determined using a spectrophotometer.Nine phenolic compounds(gallic,chlorogenic,caffeic,p-coumaric,ellagic acids,catechin,rutin,quercetin and luteolin)were detected in the native flour,with quercetin as the most abundant.The concentrations of the phenolic compounds,nephrolithiasis-associated enzymes inhibitory,and antioxidant activities of the flour decreased significantly due to deproteinization and defatting.Overall,the native flour had the highest concentrations of phenolics and the most potent enzymes inhibitory and antioxidant activities,followed by the defatted,deproteinized,and deproteinized-defatted flours.Hence,endogenous proteins and lipids may enhance the phenolics profile,anti-nephrolithiasis and antioxidant activities of M.myristica seed.This could have application in the development of functional food products and nutraceuticals targeting nephrolithiasis.展开更多
基金the financial assistance provided by ICAR-IARI in the form of IARI Fellowship and Department of Science and Technology, Innovation in Science Pursuit for Inspired Research during the PhD programme。
文摘Increased nighttime respiratory losses decrease the amount of photoassimilates available for plant growth and yield. We hypothesized that the increased respiratory carbon loss under high night temperatures(HNT) could be compensated for by increased photosynthesis during the day following HNT exposure. Two rice genotypes, Vandana(HNT-sensitive) and Nagina 22(HNT-tolerant), were exposed to HNT(4 ℃ above the control) from flowering to physiological maturity. They were assessed for alterations in the carbon balance of the source(flag leaf) and its subsequent impact on grain filling dynamics and the quality of spatially differentiated sinks(superior and inferior spikelets). Both genotypes exhibited significantly higher night respiration rates. However, only Nagina 22 compensated for the high respiration rates with an increased photosynthetic rate, resulting in a steady production of total dry matter under HNT. Nagina 22 also recorded a higher grain-filling rate, particularly at 5 and 10 d after flowering, with 1.5- and 4.0-fold increases in the translocation of ^(14)C sugars to the superior and inferior spikelets, respectively. The ratio of photosynthetic rate to respiratory rate on a leaf area basis was negatively correlated with spikelet sterility, resulting in a higher filled spikelet number and grain weight per plant, particularly for inferior grains in Nagina 22. Grain quality parameters such as head rice recovery, high-density grains, and gelatinization temperature were maintained in Nagina 22. An increase in the rheological properties of rice flour starch in Nagina 22 under HNT indicated the stability of starch and its ability to reorganize during the cooling process of product formation. Thus, our study showed that sink adjustments between superior and inferior spikelets favored the growth of inferior spikelets, which helped to offset the reduction in grain weight under HNT in the tolerant genotype Nagina 22.
文摘The bioactive compounds in a food matrix can exist either in their free form or bound to other endogenous compounds,which may affect their bioactivities.This study investigated the impact of endogenous proteins and lipids on the phenolics profile,anti-nephrolithiasis,and antioxidant activities of Monodora myristica(African nutmeg)seed.Endogenous proteins and lipids in M.myristica seed flour were removed by deproteinization and defatting,to obtain the deproteinized,defatted,and deproteinized-defatted flours.The native flour served as a control.Phenolics compounds in the flours were quantified using HPLC-DAD,while nephrolithiasis-associated enzymes(xanthine oxidase and urease)inhibitory and antioxidant activities were determined using a spectrophotometer.Nine phenolic compounds(gallic,chlorogenic,caffeic,p-coumaric,ellagic acids,catechin,rutin,quercetin and luteolin)were detected in the native flour,with quercetin as the most abundant.The concentrations of the phenolic compounds,nephrolithiasis-associated enzymes inhibitory,and antioxidant activities of the flour decreased significantly due to deproteinization and defatting.Overall,the native flour had the highest concentrations of phenolics and the most potent enzymes inhibitory and antioxidant activities,followed by the defatted,deproteinized,and deproteinized-defatted flours.Hence,endogenous proteins and lipids may enhance the phenolics profile,anti-nephrolithiasis and antioxidant activities of M.myristica seed.This could have application in the development of functional food products and nutraceuticals targeting nephrolithiasis.
