Search

Slow-controlled release fertilizers are experiencing a popularity in rice cultivation due to their effectiveness in yield and quality with low environmental costs. However, the underlying mechanism by which these fertilizers regulate grain quality remains inadequately understood. This study investigated the effects of five fertilizer management practices on rice yield and quality in a two-year field experiment: CK, conventional fertilization, and four applications of slow-controlled release fertilizer (UF, urea formaldehyde; SCU, sulfur-coated urea; PCU, polymer-coated urea; BBF, controlled-release bulk blending fertilizer). In 2020 and 2021, the yields of UF and SCU groups showed significant decreases when compared to conventional fertilization, accompanied by a decline in nutritional quality. Additionally, PCU group exhibited poorer cooking and eating qualities. However, BBF group achieved increases in both yield (10.8 t hm -2 and 11.0 t hm -2 ) and grain quality reaching the level of CK group. The adequate nitrogen supply in PCU group during the grain-filling stage led to a greater capacity for the accumulation of proteins and amino acids in the PCU group compared to starch accumulation. Intriguingly, BBF group showed better carbon-nitrogen metabolism than that of PCU group. The optimal nitrogen supply present in BBF group suitable boosted the synthesis of amino acids involved in the glycolysis/ tricarboxylic acid cycle, thereby effectively coordinating carbon-nitrogen metabolism. The application of the new slow-controlled release fertilizer, BBF, is advantageous in regulating the carbon flow in the carbon-nitrogen metabolism to enhance rice quality., (© 2024. The Author(s).)

Plant phenomics bridges the gap between traits of agricultural importance and genomic information. Limitations of current field-based phenotyping solutions include mobility, affordability, throughput, accuracy, scalability, and the ability to analyze big data collected. Here, we present a large-scale phenotyping solution that combines a commercial backpack Light Detection and Ranging (LiDAR) device and our analytic software, CropQuant-3D, which have been applied jointly to phenotype wheat (Triticum aestivum) and associated 3D trait analysis. The use of LiDAR can acquire millions of 3D points to represent spatial features of crops, and CropQuant-3D can extract meaningful traits from large, complex point clouds. In a case study examining the response of wheat varieties to three different levels of nitrogen fertilization in field experiments, the combined solution differentiated significant genotype and treatment effects on crop growth and structural variation in the canopy, with strong correlations with manual measurements. Hence, we demonstrate that this system could consistently perform 3D trait analysis at a larger scale and more quickly than heretofore possible and addresses challenges in mobility, throughput, and scalability. To ensure our work could reach non-expert users, we developed an open-source graphical user interface for CropQuant-3D. We, therefore, believe that the combined system is easy-to-use and could be used as a reliable research tool in multi-location phenotyping for both crop research and breeding. Furthermore, together with the fast maturity of LiDAR technologies, the system has the potential for further development in accuracy and affordability, contributing to the resolution of the phenotyping bottleneck and exploiting available genomic resources more effectively., (© The Author(s) 2021. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

Relevant evidence of rice quality responses to increased temperatures under field condition has been obtained in our previous study. Understanding the intrinsic mechanism of increased temperatures and fertilizer treatment in regulating rice quality formation will be contributed to the development of mitigation measures suitable for actual field operations and to cope with climate warming. This study investigated the potential role of nitrogen fertilizer in regulating the rice quality under field warming through identifying starch-related property indicators. Results showed application of nitrogen fertilizer at heading stage effectively delayed the significantly increased accumulation of total starch, amylose and amylopectin, and reduced the starch particle size, chain length distribution, and crystal structure induced by high temperature, which further compensated the deterioration of rice quality caused by elevated temperature., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Stem mechanical strength is an important agricultural quantitative trait that is closely related to lodging resistance in rice, which is known to be reduced by fertilizer with higher levels of nitrogen. To understand the mechanism that regulates stem mechanical strength in response to nitrogen, we analysed stem morphology, anatomy, mechanical properties, cell wall components, and expression of cell wall-related genes, in two varieties of japonica rice, namely, Wuyunjing23 (lodging-resistant variety) and W3668 (lodging-susceptible variety). The results showed that higher nitrogen fertilizer increased the lodging index in both varieties due to a reduction in breaking strength and bending stress, and these changes were larger in W3668. Cellulose content decreased slightly under higher nitrogen fertilizer, whereas lignin content reduced remarkably. Histochemical staining revealed that high nitrogen application decreased lignin deposition in the secondary cell wall of the sclerenchyma cells and vascular bundle cells compared with the low nitrogen treatments, while it did not alter the pattern of cellulose deposition in these cells in both Wuyunjing23 and W3668. In addition, the expression of the genes involved in lignin biosynthesis, OsPAL, OsCoMT, Os4CL3, OsCCR, OsCAD2, OsCAD7, OsCesA4, and OsCesA7, were also down-regulated under higher nitrogen conditions at the early stage of culm growth. These results suggest that the genes involved in lignin biosynthesis are down-regulated by higher nitrogen fertilizer, which causes lignin deficiency in the secondary cell walls and the weakening of mechanical tissue structure. Subsequently, this results in these internodes with reduced mechanical strength and poor lodging resistance.

Key Message: Nitrogen availability and cytokinin could promote shoot branching in rice, whereas auxin and strigolactone inhibited it. The interaction between nitrogen availability and the three hormones is discussed. Rice shoot branching is strongly affected by nitrogen availability and the plant hormones auxin, cytokinin, and strigolactone; however, the interaction of them in the regulation of rice shoot branching remains a subject of debate. In the present study, nitrogen and the three hormones were used to regulate rice tiller bud growth in the indica rice variety Yangdao 6. Both nitrogen and CK promoted shoot branching in rice, whereas auxin and SL inhibited it. We used HPLC to determine the amounts of endogenous IAA and CK, and we used quantitative real-time PCR analysis to quantify the expression levels of several genes. Nitrogen enhanced the amount of CK by promoting the expression levels of OsIPTs in nodes. In addition, both nitrogen and CK downregulated the expression of genes related to SL synthesis in root and nodes, implying that the inhibition of SL synthesis by nitrogen may occur at least partially through the CK pathway. SL did not significantly reduce the amount of CK or the expression levels of OsIPT genes, but it did significantly reduce the amount of auxin and the auxin transport capacity in nodes. Auxin itself inhibited CK synthesis and promoted SL synthesis in nodes rather than in roots. Furthermore, we found that CK and SL quickly reduced and increased the expression of FC1 in buds, respectively, implying that FC1 might be a common target for the CK and SL pathways. Nitrogen and auxin delayed expression change patterns of FC1, potentially by changing the downstream signals for CK and SL.

Flower number per panicle is one of the most important traits in rice productivity determination. The number of flowers is established in the early stages of panicle development. Nitrogen fertilizer application before panicle initiation is well known to increase flower number. Nitrogen increases cytokinin (CKs) biosynthesis in plants, and CKs have very similar effects as nitrogen fertilizer on panicle branching. The effects of nitrogen fertilizer on panicle branching may be mediated by CKs, in which accumulation in the inflorescence meristem can regulate panicle development, resulting in increased numbers of flowers and branches. Adenosine phosphate-isopentenyltransferase (IPT) catalyzes the rate-limiting step of CKs biosynthesis. We analyzed the effect of nitrogen fertilizer (urea) on the expression of OsIPT genes (OsIPTs). The results showed that OsIPTs were markedly increased, and CKs accumulated in panicle when nitrogen fertilizer was applied. CKs biosynthesis in the roots and leaves was not up-regulated by nitrogen. These results suggest that nitrogen fertilizer enhances local CKs synthesis to increase flower numbers in the panicles of rice. Localized CKs biosynthesis is an important response to nitrogen.

Nitrogen plays a central role in rice growth and development because it modulates a wide variety of processes, including cytokinin (CK) metabolism. CK-mediated signaling is also related to nitrogen metabolism. The functional relation between nitrogen and CK are extremely complex and unclear. In this study, a comparative proteomic analysis was carried out to analyze proteins regulated by nitrogen and CK in rice roots. Proteins extracted from rice roots are separated by two-dimensional polyacrylamide gel electrophoresis. Thirty-two protein spots that expressed similarly by nitrogen and CK treatments are selected for identification by mass spectrometry. Of these spots, 28 are successfully identified. These proteins were categorized into classes related to energy, metabolism, disease/defense, protein degradation, signal transduction, transposons, and unclear classification. Energy gives the largest functional category, suggesting that the glycolysis (two enzymes detected) and tricarboxylic acid cycle (six enzymes detected) are accurately regulated by nitrogen and CK, thus promoting the synthesis of amino acid. The identification of novel proteins provides new insights into the coordination of nitrogen and CK in rice. The possible role of these proteins is discussed.

There is a need to comprehensively evaluate the rice quality of different rice varieties under different nitrogen treatments. Therefore, in this study, we used twenty-one hybrid indica rice varieties and twenty-three inbred japonica rice varieties with three nitrogen fertilizer levels to investigate differences in rice qualities. As compared with hybrid indica rice, inbred japonica rice had lower coefficient of variation values for grain shape, mild rice percentage, and head rice percentage, but relatively higher coefficient of variation values for chalkiness traits, appearance, and taste value of cooked rice. A principal component analysis and membership function method were used to comprehensively evaluate the qualities of rice. The overall eating quality value by sensory evaluation and head rice percentage explained 61.3% and 67.9% of the variations in comprehensive quality of hybrid indica rice and inbred japonica rice across different nitrogen levels, respectively. We also found that rice comprehensive quality was better under low nitrogen levels for hybrid indica rice, while for inbred japonica rice, properly increasing nitrogen application could improve the comprehensive quality. [ABSTRACT FROM AUTHOR]

A reduced basal and increased topdressing fertilizer rate (RBIT) can usually increase rice yield, but whether this practice alleviates the impact of poor weather on rice production is unknown. Thus, the effect of three integrated RBIT treatments (RBITs, including RBIT alone, RBIT in combination with straw incorporation (RBITS) or a reduced fertilizer rate (RBITR)) on rice growth and nutritional status under different weathers was investigated in a 9-year experiment. Conventional fertilization (CF) was the control. We found that daytime temperature and light (DTL) after heading were the main meteorological factors limiting rice yield increases. RBITs did not affect rice yield under High-DTL, compared with CF, but RBITS significantly increased rice yield under Low-DTL. Compared with High-DTL, the positive effect of RBIT and RBITR on the N concentration and proportion in vegetative organs under Low-DTL was higher than the K concentration in vegetative organs, but RBITS showed the opposite trend. Regression analysis indicated that the harvest index had stronger correlations with the N concentration (negative), K concentration (positive), and N/K (negative) in vegetative organs under Low-DTL than under High-DTL. Our findings suggested that RBITS could improve rice adaptability to daytime temperature and light changes after heading by balancing crop nutritional status (N/K). [ABSTRACT FROM AUTHOR]

Not enough attention has been paid to the comparison in yield performance and N responsiveness between hybrid rice and inbred rice using the large number of new cultivars released after 2000 under machine transplanting. Field experiments were conducted in 2017 and 2018; 48 widely planted rice cultivars included four groups, namely indica hybrids (IHs), japonica inbreds (JIs), indica-japonica hybrids (IJHs), and indica inbreds (IIs) that were transplanted by machine with three nitrogen fertilizer levels (0, 150, 300 kg ha−1). The average yield of the hybrids (IHs, IJHs) was higher than that of JIs or IIs with a higher crop-growing rate (CGR) during the total growth duration, regardless of the N application level; moreover, longer total growth duration was responsible for the higher yield in IJHs than in IHs. The IHs had a large gap yield which mainly came from the genetic improvement in the CGR during the grain-filling stage. The yield gap was relatively small in JIs, and longer growth duration combined with optimal daily mean temperature during the grain-filling stage was the critical factor for high yield. The JIs or IJHs had higher yield under the N300 level, while the response of IHs to nitrogen varied with different cultivars. Cultivars with higher CGR during the grain-filling stage had higher yield under the N300 level. In conclusion, this study suggests that high CGR during the grain-filling stage may be a vital trait for the development of rice with high yield and high N responsiveness at machine transplanting. [ABSTRACT FROM AUTHOR]

In recent years, the application of proteomic approaches as a tool for global expression analysis and protein identification has been highly efficient in the field of plant research. A solution culture experiment involving two nitrogen treatments, 0.14 mM NHNO (low nitrogen (N)) and 1.07 mM NHNO (control), was conducted to investigate the response of rice root to low N stress. Root system architecture changed markedly under low N stress, with more lateral roots occurring on the lower part of adventitious roots and longer lateral roots on the upper part, compared to the control. A proteomic approach was employed to further study the rice responses to low N stress. Proteins extracted from roots were profiled by two-dimensional gel electrophoresis, and differentially expressed proteins were analyzed by mass spectrometry. Twelve protein spots were successfully identified by mass spectrometry, 11 of which had known functions. Of these, four were involved with the tricarboxylic acid cycle, two with adenylate metabolism, two with phenylpropanoid metabolism, and two with protein degradation. These differentially expressed proteins play an important role in the responsive mechanisms of rice root to low N stress, and uncovering how the rice proteins respond to low N stress could contribute to improving the nitrogen use efficiency. [ABSTRACT FROM AUTHOR]

Straw-derived N (Straw-N) is an important organic N source, but its distribution in soil–rice systems regulated by water management and N fertilization is poorly understood. Therefore, a pot experiment using 15N-labeled wheat residue was conducted with conventional flooded irrigation (CF) and alternate wetting/drying irrigation (AWD) both with and without N fertilization. Results showed that the whole-plant straw–N recovery rate and the soil residue rate were 9.2–11.9% and 33.5–43.1%, and 10.2–13.8% and 33.7–70.2% at panicle initiation stage (PI) and mature stage (MS), respectively. There was no interaction between water management and N fertilization. Compared to CF, AWD did not affect whole-plant straw-N absorption and significantly changed its distribution in various plant parts, such as increasing the straw-N accumulation in roots at PI and decreasing it at MS. N fertilization addition markedly promoted the transfer of straw-N to the plant but reduced the contribution rate of N uptake by the plant. Furthermore, AWD or N fertilization addition allowed more straw-N to remain in the soil, and a positive interaction effect on the straw-N loss mitigation was found. These results suggest that AWD combined with N fertilization addition is a great measure to improve the efficient utilization of straw-N and avoid the risk of environmental pollution in a soil–rice system. [ABSTRACT FROM AUTHOR]

Climate change threatens rice production by increasing the frequency of extreme temperatures during grain-filling stage (T GF). Nitrogen application can significantly affect rice yield and quality. However, the effects of interaction between T GF and nitrogen application rate on yield and quality of rice remains unclear. The objectives of this study were to comprehensively evaluate the quantitative regulatory mechanism between T GF and nitrogen application rate on rice yield and quality formation. A two-year field experiment with three varieties, five sowing dates, and three nitrogen application rates was conducted at four ecological sites in the middle and lower reaches of the Yangtze River, China in 2019 and 2020. Grain yield, milling, appearance, and eating quality were quantified for each treatment. This study demonstrated that T GF varied from 17.8 ℃ to 31.4 ℃ in different sites and sowing dates and decreased by an average of 2.1 ℃ for every 15 days the sowing date was delayed. The grain yield, head rice rate, chalky grain rate, chalkiness and taste value were all related to T GF through a quadratic function. The optimum T GF for both yield and quality of indica hybrid rice was 24.2–26.5 ℃. In terms of grain yield, nitrogen agronomic efficiency increased linearly with T GF , and nitrogen application could only confer a small increase in yield or even reduce yield under extreme low T GF. Nitrogen application alleviated the adverse effects of high T GF on rice quality, but exacerbated the deterioration of quality under low T GF. For milling and appearance quality and eating quality, the critical T GF leading to such opposite regulatory effect were identified as 23.4 ± 0.4 ℃ and 29.5 ± 0.5 ℃, respectively. The variations of the ratio of amylopectin to amylose and protein content altered texture and starch gelatinization properties, mainly explaining the differences in eating quality caused by T GF and nitrogen application rate. The present study suggests that T GF should be considered when formulating nitrogen management strategies for high-quality rice, which is crucial for alleviating the deterioration of rice quality caused by extreme T GF under global climate change. [Display omitted] • The optimum temperature during grain filling stage (T GF) for indica hybrid rice was 24.2–26.5 ℃. • Nitrogen agronomic efficiency was significantly positively correlated with T GF. • Nitrogen application could alleviate the adverse effects of high T GF on rice quality. • Nitrogen application exacerbated the deterioration of quality under low T GF. [ABSTRACT FROM AUTHOR]

• Elevated temperatures affect structural parameters of starch chain length distribution. • Nitrogen decreased the height of fifth amylopectin peak that increased at elevated temperature. • Nitrogen increased the height of second amylose peak at elevated temperature. • Nitrogen changed pasting properties and decreased relative crystallinity under warming. Nitrogen fertilization can mitigate the negative effects of high temperatures on rice. In this study, we simulated dynamic field temperature increases using a free-air temperature enhancement system. Changes in the physicochemical properties of starch were investigated under increasing nitrogen fertilization during the grain-filling stage. We observed that the application of nitrogen at elevated temperatures (ETN) did not change the chain length distribution compared with elevated temperatures (ET) alone; however, it did significantly increase the heights of the first and second amylose peaks. Specifically, ETN significantly decreased the height of fifth amylopectin and relative crystallinity, and the changes it introduced in the physicochemical properties of starch were greater than those of ET. Overall, these changes in starch properties may be associated with the ability of nitrogen to facilitate the maintenance of rice quality at high temperatures. [ABSTRACT FROM AUTHOR]

Rice glutelin is sensitive to temperature and nitrogen, however, the regulatory mechanism of glutelin response to temperature and nitrogen is unclear. In this study, we conducted the open field warming experiment by the Free-air temperature enhancement facility and application of nitrogen during grain filling. In three-year field warming experiments, glutelin relative content was significantly increased under elevated temperature and application of nitrogen. Temperature and nitrogen and their interaction increased the glutelin accumulation rate in the early and middle grain filling stages (10-25d after flowering), but decreased the glutelin accumulation rate in the middle and late grain filling stages (25-45d after flowering). Elevated temperature promoted pro-glutelin levels whereas application of nitrogen under warming increased the amount of α-glutelin. At the transcriptional level, the expression levels of the glutelin-encoding genes and protein disulphide isomerase-like enzyme (PDIL1-1), glutelin precursor accumulation 4 (GPA4), glutelin precursor mutant 6 (GPA2), glutelin precursor accumulation 3 (GPA3) and vacuolar processing enzyme (OsVPE1) of glutelin folding, transport and accumulation-related genes were up-regulated by nitrogen under natural temperature as early as 5d after flowering. However, elevated temperature up-regulated glutelin-encoding genes before 20d after flowering, and the expression of endoplasmic reticulum chaperone (OsBip1), OsPDIL1-1 , small GTPase gene (GPA1), GPA2-GPA4 and OsVPE1 were significantly increased post 20d after flowering under warming. In addition, the increase in glutelin content worsened grain quality, particularly chalkiness and eating quality. Overall, the results were helpful to understand glutelin accumulation and provide a theoretical basis for further study the relationship between rice quality and glutelin under global warming. • Elevated temperature and additional nitrogen and their interaction significantly increased the glutelin relative content. • Temperature and nitrogen and their interaction increased the glutelin accumulation rate in the early and mid-filling periods. • Elevated temperature promoted the level of pro-glutelin whereas further additional nitrogen improved the level of α-glutelin. • Glutelin synthesis and maturity were regulated by elevated temperature at 5-20d and 20-30d after flowering, respectively. [ABSTRACT FROM AUTHOR]

Abstract Due to the sensitivity of chalk formation to high temperatures, the global warming will further threaten the improvement of high chalky grain rate in the southern japonica region of China. There have been many studies reported on the role of starch in the formation of chalkiness, but the relationship between nitrogen metabolites and chalkiness has not been given sufficient attention. In this study, we conducted the open field warming experiment and investigated the effects of temperature increase on grain protein metabolism. Results showed under the warming range of predicted global temperature increase (1.9 °C–4.0 °C), field warming apparently accelerated the development of grain endosperm, and the number of protein bodies were increased in both rice varieties, Furthermore, we clarified that the increased temperature regulated the key regulatory factors in protein synthesis and metabolism pathway, and the synthesis, transport, folding, assembly process of grain protein were further affected, and that further lead the component changes of grain storage protein. In conclusion, chalky traits are closely related to the grain storage materials and in this study, increased temperature induced the changes in the accumulation balance of storage proteins, amino acids and starches, which coordinately controls the formation of grain chalkiness. Highlights • We simulated climate warming with the field-warming system in actual rice field. • Endosperm and protein bodies were apparently increased under elevated temperatures. • Elevated temperature regulated regulatory factors in protein anabolism pathway. • Elevated temperatures affect balance of storage material and induce the chalkiness. • Proteins may play a certain role in chalkiness formation under elevated temperature. [ABSTRACT FROM AUTHOR]

This study investigated the chain length distribution (CLD) of two japonica rice cultivars under six nitrogen (N) treatments by high performance size exclusion chromatography, with the aims to elucidate the effect of N on rice quality and its biological mechanism. Results showed significant influence of N on CLD. In comparison with low N rate, high N lowered the percentage of short amylopectin branches. Fitting with the CLD model of Wu-Gilbert, it suggested that relative activity of SBE to SS was lower at high N rate, thus producing fewer short amylopectin branches. Comparison of CLD between N rates and between cultivars revealed that decrease in short amylopectin branches or the relative ratio of short to long amylopcetin branches correlated with increase in flour gelatinization temperatures (T o , T p , and T c ) and decrease in pasting values (except PaT) and amylose-lipid gelatinization temperatures. In addition, quality traits of Wuyujing3, a cultivar with premium eating quality, expressed stably across N treatments compared with the high-yielding cultivar Wuyunjing7. [ABSTRACT FROM AUTHOR]

This paper reports the effect of nitrogen on amino acid composition of leaf and grain for japonica rice during the grain filling stage, using pot experiments with three N rate treatments. Dynamic changes of free amino acids (FAA) and protein amino acids (PAA) in leaves and grains were monitored. Results showed that FAA in leaves decreased with the progress of grain filling. FAA in grains increased at first 14 days after anthesis and then decreased to a nearly constant level. PAA in leaves showed a diminishing trend as leaf senesced after anthesis. Conversely, PAA in grain exhibited an increasing trend with the progress of grain filling. N had significantly positive effect on contents of FAA and PAA in leaves and grains. There was no obvious trend of the variation of FAA in leaves and grains with N rates. PAA in leaves was more sensitive to N fertilization. By contrast, PAA in grains was more stable across N rates, especially at the late stage of grain filling. In addition, composition of leaf PAA was different from that of grain, indicating the reconstruction of amino acids during the process of translocation of N compounds from leaves to grains. [ABSTRACT FROM AUTHOR]

Highlights: [•] Differences of rice lodging affected by nitrogen (N) under different eco-sites were significant. [•] For the lower lodging index (LI) rice populations, N primarily decreased the stems stiffness. [•] For the higher LI rice populations, N mainly impacted the morphological parameters of the basal stems. [ABSTRACT FROM AUTHOR]

Abstract: A field experiment involving six japonica rice cultivars with contrasting agronomic traits and seven nitrogen (N) fertilizer treatments was performed to determine the effects of N and genotype on distribution of four kinds of grain proteins and amino acids in milled and brown rice. For brown and milled rice, albumin and globulin were controlled more by genotype than N treatments, whereas prolamin and glutelin were largely determined by N. Substantial genotypic differences in response of milled/brown (M/B) ratios of proteins to N treatments were detected. In comparison with large panicle cultivars, small panicle cultivars such as Wuyujing3 had the lower ratio and exhibited more stability under contrasting N treatments. N had significant influence on amino acid composition of brown and milled rice, with contents of the 17 amino acids measured increasing with elevated N rate. However, cysteine and methionine in brown rice and lysine and methionine in milled rice were not significantly affected by N. In addition, N had little effect on ratios of M/B for most of the amino acids. [Copyright &y& Elsevier]

Abstract: Thirty-one japonica cultivars with contrasting agronomic traits were used and 5 nitrogen (N) fertilizer treatments of level and timing were performed to determine the effects of N application on grain phytic acid and proteins including albumin, globulin, prolamin, and glutelin. Variance analysis showed a large effect of N and a smaller effect of cultivar on grain phytic acid and proteins. With increased N level, grain phytic acid concentrations progressively reduced whereas concentrations of the 4 proteins and ratios of glutelin to total protein increased, indicating that N level has a beneficial effect on rice nutritional quality. In addition, substantial genotypic differences in response of grain phytic acid and proteins to N treatments were detected. Some cultivars such as Xiushui09, Zhendao10, and Yanjing5 exhibited more stability of grain proteins under contrasting N treatments, and the significance of this stability is discussed in regard to its use in rice quality improvement. [Copyright &y& Elsevier]