Determination of Self-(In)compatibility and Inter-(In)compatibility Relationships in Citrus Using Manual Pollination, Microscopy, and <em>S</em>-Genotype Analyses

Citrus uses S-RNase-based self-incompatibility to reject self-pollen and, therefore, requires nearby pollinizer trees for successful pollination and ...

https://cloudfront.jove.com/CDNSource/teasers/65056.jpg

Huazhong Agricultural University

Perturbation of the tris(2,2'-bipyridine)ruthenium(II) [Ru(bpy)(3)2+]-catalyzed Belousov-Zhabotinsky (BZ) oscillating chemiluminescence (CL) reaction induced by L-cysteine was observed in the closed system. It was found that the CL intensity was decreased in the presence of L-cysteine. Meanwhile, oscillation period and oscillating induction period were prolonged. The sufficient reproducible induction period was used as parameter for the analytical application of oscillating CL reaction. Under the optimum conditions, the changes in the oscillating CL induction period were linearly proportional to the concentration of L-cysteine in the range from 8.0 x 10(-7) to 5.0 x 10(-5 )mol L(-1) (r = 0.997) with a detection limit of 4.3 x 10(-7) mol L(-1). The possible mechanism of L-cysteine perturbation on the oscillating CL reaction was also discussed.

Perturbation of the tris(2,2'-bipyridine) ruthenium(II)-catalyzed Belousov-Zhabotinsky oscillating chemiluminescence reaction by L-cysteine and its application.

This study was conducted to evaluate the effect of farnesol (FOH) on the growth of P. expansum. The viability of P. expansum cells was determined by counting the colony forming units (CFU) after each FOH treatment. Morphological changes of FOH-treated fungal cells were analyzed by staining with Hoechst 33258, TUNEL (terminal deoxynucleotidyl transferase fluorescein-12-dUTP nick end labeling), Annexin-V FITC and the oxidant-sensitive probe H2DCFDA (dichlorodihydro-fluorescein diacetate). FOH strongly inhibited the growth of hyphae. The hyphal cells showed the hallmarks of apoptosis including chromatin condensation, DNA fragmentation, phosphatidylserine (PS) externalization, caspases activation, intracellular reactive oxygen species (ROS) generation but without nucleosomal ladder production. The abnormal cellular ultrastructure observed by transmission electron microscope (TEM) indicated that disintegration of cellular ultrastructure (especially for mitochondria) was linked to FOH-induced cell death. Taken together we demonstrated that FOH inhibits the growth of P. expansum and promotes apoptosis via activation of metacaspases, production of ROS and disintegration of cellular ultrastructure.

Farnesol induces apoptosis and oxidative stress in the fungal pathogen Penicillium expansum.

The increasing of multidrug resistance in bacterial associated infections has impaired the current antimicrobial therapy and it forces the search for other alternatives. In this study, we aimed to find the  antibacterial activity of seed coat of  against a panel of clinically important bacterial species. Ethanolic extracts of target tissues were fractionated through macro porous resin by column chromatography, using ethanol as an organic solvent with a concentration gradient of 0-100%, each along with 20% concentration increment. The minimum inhibitory (MIC) concentrations of all fractions were measured. It is found that 20% ethanolic fraction showed the most significant inhibition against tested bacterial species. All fractions were analyzed by Ultra-Performance Liquid Chromatography/mass spectrometry (UPLC/MS) and compounds were identified by comparing mass spectra with standard libraries. By pairing the identified compounds from different fractions with the antibacterial activity of each fraction, it was shown that compounds stearamide (7), 1-(4-Fluorophenyl)-2-(methylthio)-1H-imidazole-5-carboxylic acid (9) and 2,4,5 triacetoxybiphenyl (10) topped in the list for anti-bacterial activity. Further experiment with pure chemicals verified that compounds 9 and 10 have antibacterial activity against Gram-negative bacteria. Whereas, the lowest MIC value (39.06 μg/mL) was obtained by compound 10 against . Hence, the seed coat of  with its antimicrobial spectrum could be a good candidate for further bactericidal research.

Characterization of Anti-bacterial Compounds from the Seed Coat of Chinese Windmill Palm Tree ().

Forkhead/winged helix transcription factor O-class member 1 (FoxO1) is a key mediator of insulin and glucagon signaling in control of glucose homeostasis. Although epigallocatechin gallate (EGCG) has attracted interest owing to its potential to combat hyperglycemic diabetes, molecular mechanisms underlying its antihyperglycemic effect, in particular the effect on FoxO1, is poorly understand. This study aims to assess the impact of EGCG on the glucagon signaling pathway in regulating glucose metabolism. Primary hepatocytes from wild-type (WT), liver-specific FoxO1 knock out (FKO), and FoxO1-S273D knock-in (KI) mice were isolated, cultured, and treated with EGCG and/or glucagon. Our data showed the treatment of 10 μM EGCG for 6 h decreased hepatic glucose production by 20 and 23% in WT and FKO primary hepatocytes, respectively. EGCG repressed both gluconeogenesis and glycogenolysis in primary hepatocytes, coupled with activating AMPK. In addition, EGCG decreased mitochondrial oxygen consumption. We further investigated the effects of EGCG on glucagon-stimulated cAMP/PKA signaling pathway. EGCG reduced p-PKA-T197/T-PKA and p-CREB-S133/T-CREB levels by 39 and 20%, blocked p-FoxO1-S273, and suppressed nuclear FoxO1 translocation, suggesting that FoxO1 and CREB were possible downstream targets. A novel mechanism of EGCG in restraining hepatic glucose production (HGP) is through antagonizing glucagon signaling and suppressing FoxO1 via Ser273. EGCG may serve as a promising compound for regulating glucose homeostasis.

Epigallocatechin Gallate Inhibits Hepatic Glucose Production in Primary Hepatocytes via Downregulating PKA Signaling Pathways and Transcriptional Factor FoxO1.

Potato (Solanum tuberosum L.) maturity involves several important traits, including the onset of tuberization, flowering, leaf senescence, and the length of the plant life cycle. The timing of flowering and tuberization in potato is mediated by seasonal fluctuations in photoperiod and is thought to be separately controlled by the FLOWERING LOCUS T-like (FT-like) genes SELF-PRUNING 3D (StSP3D) and SELF-PRUNING 6A (StSP6A). However, the biological relationship between these morphological transitions that occur almost synchronously remains unknown. Here, we show that StABI5-like 1 (StABL1), a transcription factor central to abscisic acid (ABA) signaling, is a binding partner of StSP3D and StSP6A, forming an alternative florigen activation complex and alternative tuberigen activation complex in a 14-3-3-dependent manner. Overexpression of StABL1 results in the early initiation of flowering and tuberization as well as a short life cycle. Using genome-wide chromatin immunoprecipitation sequencing and RNA-sequencing, we demonstrate that AGAMOUS-like and GA 2-oxidase 1 genes are regulated by StABL1. Phytohormone profiling indicates an altered gibberellic acid (GA) metabolism and that StABL1-overexpressing plants are insensitive to the inhibitory effect of GA with respect to tuberization. Collectively, our results suggest that StABL1 functions with FT-like genes to promote flowering and tuberization and consequently life cycle length in potato, providing insight into the pleiotropic functioning of the FT gene.

Huimin Liu

National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops

Huazhong Agricultural University

Determination of Self-(In)compatibility and Inter-(In)compatibility Relationships in Citrus Using Manual Pollination, Microscopy, and S-Genotype Analyses

Huimin Liu

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops

Huazhong Agricultural University

Determination of Self-(In)compatibility and Inter-(In)compatibility Relationships in Citrus Using Manual Pollination, Microscopy, and S-Genotype Analyses

National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops