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Poor grain filling in inferior spikelets (IS), which is influenced by the remobilization of nonstructural carbohydrates (NSC) stored in the sheath and internode of rice plants, limits the expected high yield of large‐panicle rice. NSC remobilization from the sheath to the panicle is regulated by the T6P/SnRK1 pathway. However, in large‐panicle rice, it is unclear whether IS grain filling is related to the NSC remobilization mediated by T6P/SnRK1 signaling. In this study, two large‐panicle cultivars—W1844 and CJ03—with distinct differences in IS grain filling were used to explore the physiological mechanism mediating IS development. Compared to W1844, CJ03 IS showed lower expression of the genes related to sucrose uploading, later sucrose peaking, and delayed starch accumulation. In the CJ03, low OsSUTs expression and NSC output, transport rate, and contribution rate were detected in the sheaths and internodes. These results suggest that poor NSC remobilization results in insufficient assimilate supply for the IS, and consequently, poor IS grain filling. Furthermore, poor NSC remobilization coincided with the increased T6P content and decreased SnRK1 activity during grain filling in CJ03 IS. The expression levels of genes related to T6P metabolism and those encoding the catalytic subunit of SnRK1 were consistent with the observed T6P content and SnRK1 activity in the sheaths and internodes. Therefore, IS grain filling is potentially affected by T6P/SnRK1 signaling‐mediated NSC remobilization in large‐panicle rice. [ABSTRACT FROM AUTHOR]

Poor light stress causes lodging risks in hybrid indica rice (Oryza sativa L.) in Sichuan Basin, China. However, the effective way of improving lodging resistance of hybrid indica rice by plant regulation strategy under poor light stress has not yet been investigated. A 2‐yr field study, comparing the three foliar application uniconazole rates under normal light and shading condition, was conducted to determine the lodging resistance and its physiological mechanism by using two hybrid rice varieties (Yuxiang203 [YX203] and Cliangyouhuazhan [CLYHZ]). The results showed that shading significantly decreased grain yield, but, increased lodging index (LI) due to poor stem breaking strength (M). Also, shading increased the non‐structural carbohydrates (NSC), but reduced structural carbohydrate (SC), especially for lignin in basal culm and thus, weakened the stem stiffness. Grain yield was first increased, and then declined with increasing foliar uniconazole rates. And, LI decreased sharply owing to improvement of M while reduction of bending moment by whole plant (WP). Larger section modulus (SM) of YX203 and higher bending stress (BS) of CLYHZ were contributed to higher M. Correlation analysis showed that M was significantly correlated with culm diameter, culm wall thickness and SC content for YX203, and that with SC content for CLYHZ, respectively. The results indicated that foliar application of uniconazole increased lodging resistance of hybrid indica rice for larger M and SC accumulation in basal stem. Uniconazole foliar application at 40 mg L–1 can increase lodging resistance while maintaining grain yield of hybrid indica rice in the Sichuan Basin, China. Core Ideas: Shading rapidly raised lodging risks of hybrid indica rice due to poor stem strength of basal stem.The foliar application uniconazole increased lodging resistance of hybrid indica rice.The higher stem strength of Yuxiang203 rely on section modulus and structural carbohydrates.Uniconazole rate at 40 mg L–1 rose lodging resistance and yield of hybrid indica rice in the Sichuan Basin. [ABSTRACT FROM AUTHOR]

Belowground fertilization is a prevalent strategy for considerable grain yield and N utilization. However, the optimal fertilization depth remains uncertain in paddies, especially for slow/controlled release fertilizers. This study aimed to clarify the effect of deep "controlled‐release blended fertilizer" (CRBF) fertilization on rice (Oryza sativa L.) yield and N utilization. Two N‐fertilizer types were selected (a) urea and (b) CRBF, both combined at three fertilization depths (a) 0 cm, (b) 5 cm, and (c) 10 cm. The results showed that the grain yield was significantly affected by fertilizer type and fertilization depth. The yield achieved from CRBF was 7.8% higher than that from the urea application. Deep fertilization could also increase the rice yield with the optimum achieved from the 5‐cm depth fertilization (yield increased by 15.1% compared to that from the manual surface fertilization). Overall, the 5‐cm depth CRBF fertilization achieved the highest yield among all treatments with 12.21 and 11.84 t ha–1 for 2018 and 2019, respectively. The larger sink was the main reason for this performance. Additionally, the higher photosynthetic efficient population after earing was another principal driver to the higher yield from CRBF. Due to the higher N uptake, CRBF application increased both N partial factor productivity (PFP) and recovery efficiency (RE) (P <.05); fertilization depth also had a striking effect on PFP and RE (P <.05 or.01). The 5‐cm depth fertilization of CRBF achieved the highest N utilization for both years. The results suggest that 5‐cm depth fertilization combined with controlled‐release fertilizer is a suitable strategy for higher rice yield and N utilization. Core Ideas: The grain yield from CRBF was higher than that from the urea application treatments.Deep fertilization proved to be a strategy able to increase rice yield.The CRBF fertilization at a 5‐cm depth could achieve the optimum yield.For the yields achieved, CRBF fertilization at 5‐cm depth achieved the highest N utilization. [ABSTRACT FROM AUTHOR]

SUMMARY: The CUP‐SHAPED COTYLEDON (CUC) genes (CUC1, CUC2 and CUC3) regulate organ boundary formation in Arabidopsis. However, the functions of their homologous genes in rice (Oryza sativa) are still unknown. Here, we have identified an orthologous gene of CUC1 and CUC2 in rice, named OsNAM. Subcellular localization and yeast two‐hybrid assay results have suggested that OsNAM encodes a conserved nuclear NAC (NAM/ATAF1/CUC2) protein with a transcriptional activator. The null mutant osnam‐1 presented a fused leaf structure, small panicles, reduced branches and aberrant floral organ identities when compared with those of the wild type. Beta‐glucuronidase staining and GFP reporter lines indicated that OsNAM was expressed in young tissues and that its boundary enrichment expression was regulated by OsmiR164. Loss‐of‐function mutants for OsCUC3 resulted in no obvious defects throughout rice development. The osnam oscuc3 double mutant, however, resulted in severe leaf fusion of the first two leaves, while the osnam single mutant showed a similar phenotype from the seventh leaf. These results indicated that OsNAM and OsCUC3 act redundantly for boundary specification during post‐embryonic development. Overall, we describe the biological functions of OsNAM and OsCUC3 in rice development and the expression characteristics of OsNAM. This work reveals the important role of CUC genes in rice. [ABSTRACT FROM AUTHOR]

Key points: Enhanced carotid body chemoreflex activity contributes to development of disordered breathing patterns, autonomic dysregulation and increases in incidence of arrhythmia in animal models of reduced ejection fraction heart failure. Chronic reductions in carotid artery blood flow are associated with increased carotid body chemoreceptor activity. Krüppel‐like Factor 2 (KLF2) is a shear stress‐sensitive transcription factor that regulates the expression of enzymes which have previously been shown to play a role in increased chemoreflex sensitivity. We investigated the impact of restoring carotid body KLF2 expression on chemoreflex control of ventilation, sympathetic nerve activity, cardiac sympatho‐vagal balance and arrhythmia incidence in an animal model of heart failure. The results indicate that restoring carotid body KLF2 in chronic heart failure reduces sympathetic nerve activity and arrhythmia incidence, and improves cardiac sympatho‐vagal balance and breathing stability. Therapeutic approaches that increase KLF2 in the carotid bodies may be efficacious in the treatment of respiratory and autonomic dysfunction in heart failure. Abstract: Oscillatory breathing and increased sympathetic nerve activity (SNA) are associated with increased arrhythmia incidence and contribute to mortality in chronic heart failure (CHF). Increased carotid body chemoreflex (CBC) sensitivity plays a role in this process and can be precipitated by chronic blood flow reduction. We hypothesized that downregulation of a shear stress‐sensitive transcription factor, Krüppel‐like Factor 2 (KLF2), mediates increased CBC sensitivity in CHF and contributes to associated autonomic, respiratory and cardiac sequelae. Ventilation (Ve), renal SNA (RSNA) and ECG were measured at rest and during CBC activation in sham and CHF rabbits. Oscillatory breathing was quantified as the apnoea–hypopnoea index (AHI) and respiratory rate variability index (RRVI). AHI (control 6 ± 1/h, CHF 25 ± 1/h), RRVI (control 9 ± 3/h, CHF 29 ± 3/h), RSNA (control 22 ± 2% max, CHF 43 ± 5% max) and arrhythmia incidence (control 50 ± 10/h, CHF 300 ± 100/h) were increased in CHF at rest ( F I O 2 21%), as were CBC responses (Ve, RSNA) to 10% F I O 2 (all P < 0.05 vs. control). In vivo adenoviral transfection of KLF2 to the carotid bodies in CHF rabbits restored KLF2 expression, and reduced AHI (7 ± 2/h), RSNA (18 ± 2% max) and arrhythmia incidence (46 ± 13/h) as well as CBC responses to hypoxia (all P < 0.05 vs. CHF empty virus). Conversely, lentiviral KLF2 siRNA in the carotid body decreased KLF2 expression, increased chemoreflex sensitivity, and increased AHI (6 ± 2/h vs. 14 ± 3/h), RRVI (5 ± 3/h vs. 20 ± 3/h) and RSNA (24 ± 4% max vs. 34 ± 5% max) relative to scrambled‐siRNA rabbits. In conclusion, down‐regulation of KLF2 in the carotid body increases CBC sensitivity, oscillatory breathing, RSNA and arrhythmia incidence during CHF. [ABSTRACT FROM AUTHOR]

BACKGROUND Chalkiness has a deleterious influence on rice appearance and milling quality. We identified a notched-belly mutant with a high percentage of white-belly, and thereby developed a novel comparison system that can minimize the influence of genetic background and growing conditions. Using this mutant, we examined the differences in chemical composition between chalky and translucent endosperm, with the aim of exploring relations between occurrence of chalkiness and accumulation of starch, protein and minerals. RESULTS Comparisons showed a significant effect of chalkiness on chemical components in the endosperm. In general, occurrence of chalkiness resulted in higher total starch concentration and lower concentrations of the majority of the amino acids measured. Chalkiness also had a positive effect on the concentrations of As, Ba, Cd, Cr, Mn, Na, Sr and V, but was negatively correlated with those of B, Ca, Cu, Fe and Ni. By contrast, no significant chalkiness effect on P, phytic acid-P, K, Mg or Zn was observed. In addition, substantial influence of the embryo on endosperm composition was detected, with the embryo showing a negative effect on total protein, amino acids such as Arg, His, Leu, Lys, Phe and Tyr, and all the 17 minerals measured, excluding Ca, Cu, P and Sr. CONCLUSION An inverse relation between starch and protein as well as amino acids was found with respect to chalkiness occurrence. Phytic acid and its colocalized elements K and Mg were not affected by chalkiness. The embryo exerted a marked influence on chemical components of the endosperm, in particular minerals, suggesting the necessity of examining the role of the embryo in chalkiness formation. © 2016 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Activation of the sympathetic nervous system hastens the rate of progression and severity of chronic heart failure (CHF). Chemically sensitive nerves in the carotid body (CB) that stimulate sympathetic nerve activity become overly active in CHF and contribute to this phenomenon. The stimulus for activation of these CB chemoreceptors is not known. Blood supply to tissues is impaired due to the failing heart. In this study we tested whether a chronic reduction in blood flow to the CB may contribute to altered CB chemoreceptor function. The results show that changes that occur in CB chemoreceptor function during CHF are identical to those that occur if blood flow is simply reduced to the CB for several weeks. The results suggest that chronic impairment of blood flow may be the key step in the pathophysiological events that cause sympathetic nervous system activation in heart failure. [ABSTRACT FROM AUTHOR]

In the title compound, C(19)H(18)Br(2)O(2), the dihedral angle between the two benzene rings of the spiro-biindane molecule is 70.44 (8)°. In the crystal, mol-ecules are inter-connected along the c axis by C-H⋯O hydrogen bonds and π-π stacking [centroid-centroid distance = 3.893 (2) Å] inter-actions, forming an infinite chain structure. The chains are further inter-connected through another set of C-H⋯O hydrogen bonds, forming layers approximately parallel to the bc plane.