ABSTRACT
CrRLK1L subfamily members are involved in diverse growth- and development-related processes in Arabidopsis. However, the functions of their counterparts in rice are unknown. Here, OsANX expression was detected in developing inflorescences, mature pollen grains, and growing pollen tubes, and it was localized to the plasma membrane in pollen grains and tobacco epidermal cells. Homozygous osanx progeny could not be segregated from the CRISPR/Cas9-edited mutants osanx-c1+/- and osanx-c2+/-, and such progeny were segregated only occasionally from osanx-c3+/-. Further, all three alleles showed osanx male but not female gamete transmission defects, in line with premature pollen tube rupture in osanx-c3. Additionally, osanx-c3 exhibited precocious flowering, excessively branched inflorescences, and an extremely low seed setting rate of 1.4â¯%, while osanx-c2+/- and osanx-c3+/- had no obvious defects in inflorescence development or the seed setting rate compared to wild-type Nipponbare (Nip). Consistent with this, the complemented line pPS1:OsANX-GFP/osanx-c2 (PSC), in which the lack of OsANX expression was inflorescence-specific, showed slightly earlier flowering and overly-branched panicles. Multiple inflorescence meristem transition-related and inflorescence architecture-related genes were expressed at higher levels in osanx-c3 than in Nip; thus, they may partially account for the aforementioned mutant phenotypes. Our findings broaden our understanding of the biological functions of OsANX in rice.
ABSTRACT
Leaf angle is one of the most important agronomic traits in rice, and changes in leaf angle can alter plant architecture to affect photosynthetic efficiency and thus determine grain yield. Therefore, it is important to identify key genes controlling leaf angle and elucidate the molecular mechanisms to improve rice yield. We obtained a mutant rela (regulator of leaf angle) with reduced leaf angle in rice by EMS mutagenesis, and map-based cloning revealed that OsRELA encodes a protein of unknown function. Coincidentally, DENSE AND ERECT PANICLE 2 (DEP2) was reported in a previous study with the same gene locus. RNA-seq analysis revealed that OsRELA is involved in regulating the expression of ILI and Expansin family genes. Biochemical and genetic analyses revealed that OsRELA is able to interact with OsLIC, a negative regulator of BR signaling, through its conserved C-terminal domain, which is essential for OsRELA function in rice. The binding of OsRELA can activate the expression of downstream genes repressed by OsLIC, such as OsILI1, a positive regulator of leaf inclination in rice. Therefore, our results suggest that OsRELA can act as a transcriptional regulator and is involved in the regulation of leaf inclination by regulating the transcriptional activity of OsLIC.
ABSTRACT
OBJECTIVE: To investigate the vascular damage effects and possible mechanism of acute exposure to ozone (O3) in male Wistar rats. METHODS: One hundred and twenty male Wistar rats were randomly divided into six groups, 20 in each group. The experimental animals were placed in a gas poisoning cabinet, the control group was exposed to filtered air, and the treatment group was exposed to ozone at concentrations of 0.12 ppm, 0.5 ppm, 1.0 ppm, 2.0 ppm, and 4.0 ppm, respectively, for 4 hours. Arterial blood pressure data were obtained by PC-lab medical physiological signal acquisition system. Blood rheology indicators and blood biochemical indicators were detected by Tianjin Dean Diagnostic Laboratory. Serum endothelin-1 (ET-1), homocysteine (HCY), von Willebrand factor (vWF), 8-hydroxydeoxyguanosine (8-OhdG), interleukin (IL-6) and tumor necrosis factor alpha (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA) microplate assay. Oxidative stress indicators superoxide dismutase (SOD) activity and malondialdehyde (MDA) were determined by xanthine oxidase method, thiobarbituric acid (TBA) method, reduced glutathione (GSH) and nitric oxide (NO) were tested by using microplate colorimetry. Paraffin sections were prepared from thoracic aorta tissue, and vascular structure was observed by HE staining. RESULTS: Acute exposure to 0.12 ppm ozone could cause a significant increase in arterial systolic blood pressure (SBP). Exposure to different concentrations of ozone could cause a significant increase in plasma viscosity, and the K value of the ESR equation was significantly increased in the 1.0 ppm ozone exposure group. Both the relative and reduced viscosities were significantly reduced at ozone concentrations of 0.5 ppm and 4.0 ppm, while the red blood cell deformation index was increased significantly at ozone concentrations of 0.12 ppm, 0.5 ppm, 1.0 ppm, and 2.0 ppm. Acute ozone exposure resulted in the decrease of total cholesterol content. The content of high-density lipoprotein cholesterol (HDL-C) was significantly reduced in the 0.12 ppm ozone exposure group. When the ozone concentration was higher than 1.0 ppm, the body may also had an inflammatory reaction (increased TNF-α) and oxidative stress (increased MDA, decreased GSH). Acute exposure to ozone could lead to elevated levels of ET-1 in the blood, with significant differences in the 4.0 ppm concentration group, while HCY levels were decreased firstly and then increased, reaching the highest in the 1.0 ppm concentration group. No obvious pathological changes were observed in the thoracic aorta. CONCLUSION: Acute ozone exposure can affect arterial blood pressure, blood rheology and cholesterol metabolism in rats. The possible mechanism is that ozone exposure leads to inflammatory reaction and oxidative stress reaction, causing vascular endothelial function damage, and vascular endothelial cells increase with ozone exposure concentration.
