Molecular Characterization and Expression Analysis of a Gene Encoding 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGR) from Bipolaris eleusines, an Ophiobolin A-Producing Fungus.

Ophibolin A, a fungal sesterterpene, exerts a pivotal influence in a diverse array of biological processes, encompassing herbicidal, bactericidal, fungicidal, and cytotoxic activities. Sixty genes associated with sesterterpene compound biosynthesis were obtained from Bipolaris eleusines via transcriptome sequencing, and those closely linked to ophiobolin A biosynthesis were subsequently filtered. A gene encoding 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) that catalyzes the first committed step of ophiobolin biosynthesis in the mevalonic acid (MVA) pathway was isolated and characterized using RACE (Rapid Amplification of cDNA Ends) technology from ophiobolin A-producing fungus, B. eleusines. The full-length cDNA of the B. eleusines HMGR gene (BeHMGR) was 3906 bp and contained a 3474 bp open reading frame (ORF) encoding 1157 amino acids. Sequence analysis revealed that deduced BeHMGR had high homology to the known HMGRs from Pyrenophora tritici-repentis and Leptosphaeria maculans. It had a calculated molecular mass of about 124.65 kDa and an isoelectric point (pI) of 6.90. It contained two putative HMG-CoA-binding motifs and two NADP(H)-binding motifs. Induced expression analysis of the BeHMGR gene by methyl jasmonate treatment using quantitative fluorescence PCR showed that it significantly elevated after 3 h of methyl jasmonate treatment, peaked at 6 h, and then gradually decreased. This demonstrates that BeHMGR gene expression is induced by methyl jasmonate.

Improved Bioherbicidal Efficacy of Bipolaris eleusines through Herbicide Addition on Weed Control in Paddy Rice.

Bipolaris eleusines was mixed with herbicides to improve the control of barnyardgrass (Echinochloa crus-galli), a noxious weed in rice fields. The compatibility of B. eleusines with herbicides was evaluated for toxic effects on spore germination and mycelium growth in vitro tests, and varied effects were observed with different chemical products. Briefly, 25 g/L penoxsulam OD plus 10% bensulfuron-methyl WP were much more compatible with B. eleusines, and there was no inhibition of spore germination but the promotion of mycelium growth of B. eleusines at all treatment rates. Under greenhouse conditions, the coefficient of the specificity of B. eleusines conidial agent was determined as 3.91, closer to the herbicidal control of 2.89, showing it is highly specific between rice and barnyardgrass. Field experiments in 2011 and 2012 showed that B. eleusines conidial agent displayed good activity on barnyardgrass, monochoria [Monochoria vaginalis (Burm.f.) Presl. Ex Kunth.], and small-flower umbrella sedge (Cyperus difformis L.) and had no negative impact on the rice plant. It also reduced the loss of rice yield when compared with the non-treated control and could make this pathogen a conidial agent for commercial bioherbicidal development in the future.

Lens nuclear opacity quantitation with long-range swept-source optical coherence tomography: correlation to LOCS III and a Scheimpflug imaging-based grading system.

PURPOSE: To quantitate lens nuclear opacity using long-range swept-source optical coherence tomography (SS-OCT) images and to evaluate the correlation of this method to Lens Opacities Classification System III (LOCS III) and a Scheimpflug imaging-based grading system (Pentacam Nuclear Stage function; PNS). METHODS: This study enrolled 120 participants (120 eyes) with age-related nuclear cataracts. The best-corrected visual acuity (BCVA), LOCS III nuclear opalescence (NO) and nuclear colour (NC) were obtained. The nuclear density measured using PNS function (NDPNS) was recorded. Three successive series of long-range SS-OCT images were captured, and the nuclear region was analysed using ImageJ (NIH, Bethesda, Maryland, USA) to generate SS-OCT image-based nuclear density (NDSS-OCT). The repeatability of NDSS-OCT measurement was evaluated using within-subject coefficient of variation (CVw) and intraclass correlation coefficient (ICC). Correlations of NDSS-OCT with NO and NC, BCVA and NDPNS were analysed. According to the integrity of nucleus imaged by Pentacam, patients were divided into two groups, and the parameters were compared between groups. RESULTS: The CVw and ICC for NDSS-OCT measurement were 1.5 % and 0.994, respectively. The NDSS-OCT significantly correlated with NO (r=0.831), NC (r=0.873), BCVA (r=0.655) and NDPNS (r=0.891). The NDSS-OCT, NO and NC, and BCVA were significantly different between the two groups. CONCLUSION: Lens nuclear opacity quantitation using long-range SS-OCT images was repeatable and correlated well with LOCS III and PNS function. The Scheimpflug principle had a limitation in imaging dense nucleus. Long-range SS-OCT seems more promising for objectively and quantitatively assessing lens nuclear opacity.

Dysfunctional Lens Index Serves as a Novel Surgery Decision-Maker for Age-Related Nuclear Cataracts.

Purpose: To study the correlations between subjective and objective cataract metrics with dysfunctional lens index. To investigate the potential of the DLI as a novel surgery decision-maker. Methods: In this prospective, cross-sectional study, we measured the dysfunctional lens index (DLI), Lens Opacities Classification System III nuclear opalescence (LOCS III NO) grading, preoperative corrected distance visual acuity (CDVA), objective scatter index (OSI) and Scheimpflug-based average lens density (ALD) in eyes with nuclear cataract. Eyes were classified as Surgical and Non-Surgical groups. Correlations among the DLI, OSI, ALD, LOCS III NO grading, and preoperative CDVA were analyzed. The receiver operating characteristic (ROC) curve analysis was performed for DLI, OSI, and CDVA to determine optimal cut-off values to separate between surgical and non-surgical cataracts. Results: The DLI showed the strongest correlation with the OSI (r= -0.712, P< .001), followed by LOCS III NO score (r= -0.661, P< .001), ALD (r= -0.596, P< .001) and preoperative CDVA (r= 0.563, P< .001). The area under ROC curves (AUCs) of the DLI, OSI and preoperative CDVA curve were 0.972, 0.912 and 0.844 (All P< .001), respectively. The DLI cut-off value of 5.7 implied higher levels of sensitivity (91.67%) and specificity (91.84%) than the OSI cut-off value of 2.9 and the CDVA cut-off value of 0.55 (sensitivity of 89.58% and 71.92%; specificity of 81.63% and 85.71%, respectively). Conclusion: The surgery criterion of DLI ≤ 5.7 behaved better than the surgery criterions of OSI ≥ 2.9 and preoperative CDVA ≤ 0.55 in discrimination between surgical and non-surgical nuclear cataracts.

Morphological and biometric features of preexisting posterior capsule defect in congenital cataract.

PURPOSE: To describe the diagnostic signs and biometric characteristics of preexisting posterior capsule defects in congenital cataract. SETTING: Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China. DESIGN: Retrospective case series. METHODS: Eyes with congenital cataract were reviewed and divided into a preexisting posterior capsule defect group (study group) and a control group with intact posterior capsules. Diagnostic signs were summarized on agreement of 3 ophthalmologists after they reviewed surgical videos. The biometric parameters, including central corneal thickness, anterior chamber depth, lens thickness, vitreous chamber depth, axial length, mean keratometry, corneal astigmatism, corneal diameter, and intraocular pressure, were compared between groups. The predictors of preexisting posterior capsule defect were determined using univariate and multivariate analyses. RESULTS: The study comprised 81 eyes (53 patients). The diagnostic signs of preexisting posterior capsule defect included posterior capsule plaque with a well-demarcated margin, gray granules and vacuoles, and heterogeneous nuclear opacity (more dense in the posterior). The lens was significantly thinner in the study group than in the control group (P < .001). The corneal diameter was significantly smaller in the study group (P = .015 horizontal and P = .005 vertical). Multivariate analysis identified lens thickness as an independent predictor (odds ratio, 0.731; 95% confidence interval, 0.621-0.860; P < .001). CONCLUSIONS: For preexisting posterior capsule defect, lens thickness was a valuable predictor and the presence of characteristic morphology was an important indicator. The cornea configuration suggests the need for further study of the role of genetic mutation.

[A isolation and identification of an antioxidant from Monochoria vaginalis].

With solvent extraction, a total of four fractions were separated from 75% alcohol extract of Monochoria vaginalis, and their antioxidative activities were measured by iodine method. The results showed that among the fractions, n-butanol fraction exhibited the highest antioxidative activity, which was not only significantly higher than CK (water), but also equivalent to the natural antioxidant tea polyphenols and synthetic antioxidant butylated hydroxyl toluene (BHT). A compound was isolated from the n-butanol fraction by using column chromatography, and identified as stigmasterol 3-O-beta-D-glucopyranoside. Its antioxidative activity estimated by the determination of the percentage of scavenged free radicals indicated that this compound exhibited a higher activity than BHT in scavenging free radicals.

[Stress-resistance of weedy rice Luolijing (Oryza sativa)].

Weedy rice Luolijing (Oryza sativa) is generated in Dandong, Liaoning Province of Northeast China. Its plant height is taller than normal planted rice varieties, and its caryopsis is medium or long in size, which dropped easily after matured. The color of the caryopsis shell is straw-like or yellow alternated with black-gray. The spikelet is with or without awns, and the length of the awns is 2-12 cm. The 1000 caryopsis weight is 23.5 g, and the hull is nacarat. The seed germination rate at 13-38 degrees C is > 88%. Under 2.5-10 cm water flooding, the plant dry weight reduced 50%-69%. At seedling stage, Luolijing had a stronger resistance capability against barnyardgrass (Echinochloa crusgalli var. mitis) than an alellopathic rice I-kung-pao, which meant that Luolijing had no allelopathic function. The Luolijing had a tolerance to 0.5% saline-alkaline solution.

[Competition and allelopathy of rice isogenic lines having similar genetic background but different plant morphology against weed].

Zhefu 802 rice isogenic lines IG1, IG4, IG25 and IG26 have the same genetic background but different plant morphology. This paper studied their competition and allelopathy against barnyardgrass. The results showed that IG1 and IG4 had higher plant height, bigger tiller angle and less root vitality than IG25 and IG26, and provided 15% and 17% control of barnyardgrass plant dry weight, which were significantly higher than IG26. The competition ability of test rice isogenic lines against the weed was positively correlated with their plant height and tiller angle, but negatively correlated with their root vitality. The inhibition rate of the water extract of IG1 leaves on barnyardgrass root length was 77.6%, significantly higher than that of non-allelopathic material Xiushui 63, while the IG4 which has the similar plant morphology with IG1 didn't show any significant allelopathy. It seems that there were no correlations between allelopathy and morphological characters of rice under the same genetic background.

[Rice allelopathy to barnyardgrass].

138 rice (Oryza sativa) germplasms were identified to study the allelopathy to barnyardgrass (Echinochloa crusgalli), using the relay seeding technique. The results showed that Qingkun 2 from Jiangxi Province, Xiayitiao from Jiangsu Province, Jizaoxian from Anhui Province, Ganzaoxian 37 from Jiangxi Province, Shangnuo 1, IR68465-2-3-2 from IRRI, and Shuiyuan 2 from Korea had a strongly excellent inhibition effect on barnyardgrass. Results from pot culture showed that Gumei 2 and Zhong 156 had a greater inhibitory effect than control, and allelopathic material TN1 had no significantly inhibition effect, compared to non-allelopathic material Xiushui 63. The effect of Zhong 156 was related to its plant height, and significant different from that of Xiushui 63. Gumei 2 had a stronger inhibition effect on barnyardgrass, due to its own allelopathic trait.

[Molecular biological study on the action mechanism of rice allelochemicals against weeds].

Rice allelopathy is implemented through its release of allelochemicals to environment. Many researchers considered that rice allelochemicals were phenolics. The action mechanisms of rice against weeds allelochemicals included the inhibition of seed germination and emergence, the effect on the balance of hormones, the damage on the integrity of cell membrane systems, the effect on photosynthesis and respiration, the disturbance of nutrient and water uptake and the effect on the protein synthesis and gene expression. Rice allelopathy is controlled by polygenes, and inherited quantitatively. Several QTLs were identified by the methods of molecular biological techniques and allelopathic bioassay. It might be the important research work to locate the QTLs accurately and to clone the allelopathic genes with the method of marker-assisted selection and the near isogenic lines.