Brassinosteroid regulation in rice seed biology

Rice(Oryza sativa L.)is not only a model monocotyledon plant,but also an important cereal seed crop.Improvements in seed-related traits is the key to obtaining high grain yield and quality,therefore attracting attention from both scientists and crop breeders.In higher plants,brassinosteroid(BR),a major growth-promoting hormone,plays an important role in regulating numerous agronomic traits associated with both vegetative and reproductive growth,thereby presenting huge application potential.Here,we review recent progress into BR regulation in rice seed biology.Both BR biosynthesis and signaling have been shown to regulate grain size,grain filling,grain number,seed germination and biosynthesis of seed components.Thus,considering the pleiotropic effects of BR,strategies aimed at genetic modulation of the BR pathway have been proposed to improve seed-related traits in rice,and therefore,enhance both yield and quality.This review not only strengthens our understanding of the underlying mechanism and regulatory network of BR-regulated key agronomic traits in rice,but also facilitates the future application of BR in rice breeding programs.

Cryopreservation of amphioxus (Branchiostoma belcheri) spermatozoa

Amphioxus, Branchiostoma belcheri, a closest relative of vertebrates, is at a high risk of extinction due to a combination of low effective population size, altered native habitats and environmental pollution, yet little is known about cryopreservation of its gametes. This study deals with the cryopreservation of amphioxus senlen. The main findings are that （1） the extender of Yao et al. is the best one among the four extenders examined; （2） the appropriate ratio of semen to extender of Yao et al. plus cryoprotectant is from 1：5 to 1：7; （3） dimethyl sulfoxide （DMSO） and methanol are the better cryoprotectants than glycerol, with DMSO giving the best results; （4） the eggs fertilized with post-thaw spermatozoa are capable of developing to at least hatching stage, and the highest hatching rate is （12.4±3.0）%. This is the first report on freezing and thawing of amphioxus spermatozoa, providing a simple and practical protocol for cryopreservation of amphioxus spermatozoa and laying a foundation for safeguarding this endangered species.

Proteomic analysis provides insights into the function of Polian vesicles in the sea cucumber A postichopus japonicus post-evisceration

The Polian vesicle is the main accessory structure in the water vascular system of sea cucumbers.It can function to hold water vascular fluid under slight pressure and act as a hematopoiesis,excretory,and inflammatory response organ.Being the only organ to remain after evisceration,the Polian vesicle may function in the survival and regeneration of sea cucumber.We performed Tandem Mass Tag(TMT)-based proteomics to identify how proteins in the Polian vesicle of Apostichopus japonicus respond to evisceration.Among the 8453 proteins identified from vesicle samples before evisceration(PVOh)and at 6-h post-evisceration(PV6h)and 3-d post-evisceration(PV3d),we detected 222 differentially abundant proteins(DAPs).Most of the annotated DAPs were associated with cell growth and proliferation,immune response and wound healing,substance transport and metabolism,cytoskeleton/cilia/flagella,extracellular matrix,energy production and conversion,protein synthesis and modification,and signal recognition and transduction.Compared with PVOh,fewer DAPs were identified at PV6h,and more DAPs were found at PV3d,and these DAPs were widely distributed among multiple biological processes.Our results indicate that a wide range of biological processes was induced in Polian vesicles in response to evisceration.In particular,Polian vesicles may play important roles in the re storation of coelomocyte s,immune defense,and wound healing in sea cucumber.We propose that the Polian vesicle may be involved in visceral regeneration through nutrition and energy supply and by promoting dedifferentiation and migration.Together,these results provided new insights into the function of the Polian vesicle in A.japonicus post-evisceration.

The immunoreactivity of Cra a 4 decreased after Maillard reaction with xylose and glucose

Cra a 4 is a heat stable allergen in oyster,the effect of Maillard reaction on the immunoreactivity and structure of Cra a 4 was investigated.Firstly,Cra a 4 was cloned,expressed and identified.The purified Cra a 4 was incubated with xylose at 100℃,pH 8.5 for 30 min or with glucose for 60 min.After Maillard reaction,the IgE-binding activity of Cra a 4 and in vitro digested samples was reduced by about 50%.The unfoldα-helix and higher surface hydrophobicity of glycated Cra a 4 were identified as the reason for hypo-immunoreactivity.The higher frequency of lysine(13%)in the primary structure and exposure on the surface of the spatial structure was attributed to the hypo-immunoreactivity of Cra a 4 after Maillard reaction.It comprehensively evaluated the effects of Maillard reaction on Cra a 4 and provids new methods for the industrial production of hypoallergenic oyster.The modified Cra a 4 by Maillard reaction could be a hypoallergenic therapeutic agent for allergy to oyster.

Enhancing the immune response in the sea cucumber Apostichopus japonicus by addition of Chinese herbs Houttuynia cordata Thunb as a food supplement

The Chinese herb Houttuynia cordata Thunb(abbreviated as HCT hereafter)has been widely used in human and livestock medical research.However,few studies have tested the effects of HCT in aquaculture systems,particularly in echinoderms.In this study,the impact of HCT was evaluated when used as a feed additive to enhance the immune response of the sea cucumber,Apostichopus japonicus.Two concentrations,1.5%and 3%,of HCT powder were tested by adding them to the feed.Feeding experiments had a four week duration and each week,the humoral and cellular immunity index of the intestine,tentacles,peristome,and coelomic fluid were analyzed.The results indicated that the percentage of A.japonicus coelomocytes significantly increased after supplementing feed with HCT,and reached a peak after one week of feeding with the 3%HCT supplementation.Analysis of reactive oxygen species(ROS)indicated that HCT in feed caused a notable increase in the coelomocyte ROS concentrations over the experimental period.In both the 1.5%and 3%HCT addition groups,the ROS peaked in the third week and then remained stable.In addition,alkaline phosphatase,acid phosphatase,superoxide dismutase,lysozyme activity of the intestine,tentacles,peristome and coelomic fluid were significantly improved during the four-week test period.In conclusion,1.5%and 3%HCT added to feed boosts the immune responses of A.japonicus.HCT has potential as an immune enhancer for mariculture of sea cucumbers.

Monoclonal antibody based Dot-ELISA and indirect fluorescence antibody technique for detecting Edwardsiella ictaluri infection in yellow catfish (Pelteobagrus fulvidraco)

Edwardsiella ictaluri is known as the etiological agent of Red-head disease of yellow catfish(Pelteobagrus fulvidraco),and is the cause of heavy economic losses in the aquaculture industry.In this study,a DotEnzyme Linked Immunosorbent Assay(Dot-ELISA)and an Indirect Fluorescence Antibody technique(IFAT)for detecting Edwardsiella ictaluri were developed by using a monoclonal antibody,5D11.For DotELISA,the working dilutions of 5D11 and the secondary antisera(enzyme-labeled goat anti-mouse Ig)were 1:320 dilution and 1:3000 dilution,respectively.For IFAT,the working dilutions of 5D11 and goatanti-mouse Ig conjugated with fluorescein isothiocyanate were as respectively 1:80 and 1:256.Both of the methods established were highly sensitivity(Minimum detectable concentration,5
107 CFU/mL)and had a high degree of accuracy(positive rate was 100%for both artificial infected fish and spontaneous diseased Pelteobagrus fulvidraco).The two reliable methods developed have high potential for quick and efficient detection of Edwardsiella ictaluri in aquaculture production units.