水稻qGL3.4调控籽粒大小与株型

籽粒大小与株型对水稻产量具有重要影响,因此其相关基因克隆与功能研究对培育高产水稻具有重大的意义。本研究从以短舌野生稻为供体、华粳籼74 (HJX74)为受体的染色体单片段代换系(SSSLs)中鉴定到一个新的调控籽粒大小与株型的QTL位点qGL3.4。与对照HJX74相比,近等基因系NIL-qGL3.4的粒长、粒宽、千粒重、穗长、穗粒数、一次枝梗数、单株产量与株高显著增加,而NIL-qGL3.4的分蘖数和二级枝梗数与HJX74对应值无显著差异。通过图位克隆,将qGL3.4定位在第3号染色体239.18 kb区间内。细胞学分析表明,NIL-qGL3.4通过调节颖壳细胞的生长进而调控籽粒的大小。分子机理研究表明,qGL3.4可能通过调控籽粒大小相关基因EXPANSINs、GS3、GL3.1、PGL1、GL7、OsSPL13和GS5的表达进而调控籽粒大小。本研究可能为高产与理想株型的水稻培育提供新的靶标位点。

GL9 from Oryza glumaepatula controls grain size and chalkiness in rice

Grain size is a key factor influencing grain yield and appearance quality in rice.We identified twelve quantitative trait loci(QTL)for grain length(GL),nine for grain width(GW),and nine for 1000-kernel weight(TKW)using GLU-SSSLs,which are single-segment substitution lines with Oryza glumaepatula as donor parent and Huajingxian 74(HJX74)as recipient parent.Among the QTL,qGL1-2,qGL1-4,qGL9-2,qGW2-2,qGW9-1 and qTKW9-2 contributed to high grain yield.GL9 was identified as a candidate gene for qGL9-2 by map-based cloning and sequencing,and is a novel allele of GS9.The kernel of NIL-gl9was slenderer and longer than that of HJX74,and the TKW and grain yield per plant of NIL-gl9 were higher than those of HJX74.The proportion of grain chalkiness of NIL-gl9 was much lower than that of HJX74.Thus,gl9 increased grain yield and appearance quality simultaneously.Three pyramid lines,NIL-gs3/gl9,NIL-GW7/gl9 and NIL-gw8/gl9,were developed and the kernel of each was longer than that of the corresponding recipient parent lines.The gl9 allele may be beneficial for breeding rice varieties with high grain yield and good appearance quality.

Highly specific characterization and discrimination of monosodium urate crystals in gouty arthritis based on aggregation-induced emission luminogens

Existing technologies used to detect monosodium urate(MSU)crystals for gout diagnosis are not ideal due to their low sensitivity and complexity of operation.The purpose of this study was to explore whether aggregation-induced emission luminogens(AIEgens)can be used for highly specific imaging of MSU crystals to assist in the diagnosis of gout.First,we developed a series of luminogens(i.e.,tetraphenyl ethylene(TPE)-NH_(2),TPE-2NH_(2),TPE-4NH_(2),TPE-COOH,TPE-2COOH,TPE-4COOH,and TPE-Ketoalkyne),each of which was then evenly mixed with MSU crystals.Next,optimal fluorescence imaging of each of the luminogens was characterized by a confocal laser scanning microscope(CLSM).This approach was used for imaging standard samples of MSU,hydroxyapatite(HAP)crystals,and mixed samples with 1:1 mass ratio of MSU/HAP.We also imaged samples from mouse models of acute gouty arthritis,HAP deposition disease,and comorbidities of interest.Subsequently,CLSM imaging results were compared with those of compensated polarized light microscopy,and we assessed the biosafety of TPE-Ketoalkyne in the RAW264.7 cell line.Finally,CLSM time series and three-dimensional imaging were performed on MSU crystal samples from human gouty synovial fluid and tophi.As a promising candidate for MSU crystal labeling,TPE-Ketoalkyne was found to detect MSU crystals accurately and rapidly in standard samples,animal samples,and human samples,and could precisely distinguish gout from HAP deposition disease.This work demonstrates that TPE-Ketoalkyne is suitable for highly specific and timely imaging of MSU crystals in gouty arthritis and may facilitate future research on MSU crystal-related diseases.

Coking kinetics and influence of reaction-regeneration on acidity, activity and deactivation of Zn/HZSM-5 catalyst during methanol aromatization

The coking kinetics and reaction-regeneration on Zn/HZSM-5 （Zn/HZ） catalyst in the conversion of methanol to aromatics were investigated. The highest initial benzene, toluene and xylene （BTX） yield of ca. 67.7% was obtained on fresh Zn/HZ catalyst, which showed the worst catalytic stability. The cycle of reaction-regeneration significantly modified the texture and acidity of Zn/HZ catalyst, which in turn affected its catalytic performance and coking behavior in methanol conversion to BTX. The residual carbon located on the surface of Zn/HZ catalyst led to the decrease of acid sites and the change on the acid sites distribution, which played an important roles on its activity and deactivation. It was found that the high B/L ratio and the low total acid sites concentration of the Zn/HZ catalyst favored to the high BTX yield and good catalytic stability in methanol conversion.

Target chromosome-segment substitution: A way to breeding by design in rice

Progress in plant breeding depends on the development of genetic resources,genetic knowledge,and breeding techniques.The core of plant breeding is the use of naturally occurring variation.At the beginning of the post-genomic era,a new concept of"breeding by design"was proposed,which aims to control all allelic variation for all genes of agronomic importance.In the past two decades,we have applied a three-step strategy for research on rice breeding by design.In the first step,we constructed a singlesegment substitution line(SSSL)library using Huajingxian 74(HJX74),an elite xian(indica)rice cultivar,as the recipient in which to assemble genes from the rice AA genome.In the second step,we identified a series of desirable genes in the SSSL library.In the third step,we designed new rice lines,and achieved the breeding goals by pyramiding target genes in the HJX74-SSSL library.This review introduces the background,concept,and strategy of breeding by design,as well as our achievements in rice breeding by design using the HJX74-SSSL platform.Our practice shows that target chromosome-segment substitution is a way to breeding by design.

High-throughput sequencing analysis of the regulation of intestinal flora in giant pandas with indigestion using a probiotic agent LyPB

This study aimed to investigate the eff ect of LyPB on the intestinal microfl ora of giant pandas with indigestion,using high-throughput sequencing(HTS)technology.The species distribution and microfl oral density and diversity before and after administration of the LyPB probiotic agent were analyzed.LyPB evidently has the ability to adjust the fl oral imbalance in the panda’s intestine.To test the eff ects of LyPB on the microfl ora of the panda gut,fecal samples were taken from a healthy giant panda(Anan)without administration of LyPB and from a dyspeptic giant panda Yangyang before and after LyPB administration.Compared with the sample obtained from healthy Anan(anan-c)and that obtained from dyspeptic Yangyang before LyPB administration(yangyang1),the sample taken from Yangyang(yangyang2)after LyPB administration displayed a signifi cant increase in the operational taxonomic unit index.An increase in the Chao index indicated an increase in the microfl oral richness,while an increase in the Shannon index indicated an increase in microfl oral diversity.At phylum and genus levels,a signifi cant increase was observed in the density of probiotic bacteria of phylum fi rmicutes,genus Streptococcus,while a drastic reduction in the density of Escherichia coli/Escherichia coli Shigella/bacteria of genus Shigella was observed.Data obtained in this study shows that LyPB preparations successfully improve the microbial structure within the panda’s intestinal canal by signifi cantly increasing the eff ective microbial community and decreasing the number of pathogenic microbes.

Seasonal variations in the plant diet of the Chinese Monal revealed by fecal DNA metabarcoding analysis

The Chinese Monal(Lophophorus thuysii)is an alpine-obligate galliform species of global conservation priority.It has been listed as a first class protected wildlife species in China,requiring conservation actions during the 14 th Five-Year Plan period.However,the diet composition of Chinese Monal and its seasonal variations have rarely been studied,constraining the effective conservation of the species.Here,we investigated the plant diet composition of the Chinese Monal and its seasonal variations using a DNA metabarcoding approach on fecal samples.We collected 190 fecal samples of the Chinese Monals from the central Qionglai Mountains located in China,and analyzed the plant diet of this species using a DNA metabarcoding approach.Taxonomic profiling of higher plants in the fecal samples was performed using the second internal transcribed spacer(ITS2)amplicon.Downstream analyses,including rarefaction curves,nonmetric multidimensional scaling(NMDS)and permutational multivariate analysis of variance(PERMANOVA),were used to explore the seasonal variations in diet composition.The Chinese Monal foraged a wide range of plant recipes composed of 35 families and 83 genera throughout the year,with Brassicaceae,Apiaceae,and Poaceae as the dominant families,and Cardamine as the dominant genus.The species consumed plants from 62 genera from 28 families during the breeding season(n=81)and 66 genera from 31 families during the non-breeding season(n=109).Further,the plant diet composition significantly varied between the breeding and non-breeding seasons,especially for the frequency of occurrence and relative read abundances at genus level.Our study analyzed the plant diet of the Chinese Monal at a high resolution for the first time,and the results revealed that the seasonal variations in its plant diet composition was adapted to plant phenology and foraging strategy.Fritillaria species,a previously confirmed important food resource for the Chinese Monal,were not detected in any fecal samples,potentially due to overharvesting of Fritillaria bulbs for Traditional Chinese Medicine.Therefore,we highly recommend further restriction of herb gathering in Chinese Monal habitats to facilitate the conservation of this endangered species.Altogether,our study enriches essential ecological information for the Chinese Monal and also provides insights into conservation management for this endangered species.

Seismic sentinel? An analysis of captive giant panda behavior in response to the Lushan earthquake in China

It is widely believed that various animal species can sense and respond to the geophysical stimuli that precede earthquakes,especially electromagnetic fields,although supporting field evidence is mostly anecdotal.Here we report on the reactions of four female giant pandas under observation over the three days prior to the Lushan(30.1°N,103.0°E)magnitude 7.0 earthquake that occurred in Sichuan province,China,on April 20,2013.We observed no significant generalized behavioral anomalies indicative of them perceiving an impending earthquake.We also observed no startle behaviors in the 5 s prior to tremors commencing,indicating that these pandas either did not detect or did not respond to precursor P-waves.Our findings suggest that although giant pandas have evolved in,and continue to occupy exclusively,a seismically active range in central China,they do not appear to perceive pre-earthquake geophysical warning signs.

Giant panda(Ailuropoda melanoleuca)neonates use broadband calls to communicate with their mothers

Infant call structure should have evolved to elicit maximum maternal attention and investment.Neonates of giant pandas produce three types of vocalizations reported to be vitally important in the context of mother–infant communications.However,how cubs,0–15 days old,communicate with their mothers to elicit maternal care remains unknown.We analyzed 12 different call parameters of 3475 squawks,1355 squalls,and 491 croaks from 11 captive giant panda(Ailuropoda melanoleuca)neonates from age 0 to 15 days.In playback experiments,we also tested whether mothers could detect ultrasound.Our results show that neonates use broadband calls with ultrasonic frequencies up to 65 kHz to convey information about their physiological needs and to attract maternal care.In playback experiments,we tested if mothers reacted differently to broadband calls(BBC)than to artificially altered calls that included only frequencies<20 kHz(AUDC)or calls that included only frequencies>20 kHz(USC).Playback confirmed that,although adult females responded significantly less often to USC,BBC than to or AUDC,they could detect USC,BBC and generally made appropriate behavioral responses,indicating a potential benefit for neonates to utilize ultrasonic and broadband frequencies.Our findings provide a new insight into mother–infant communication in giant pandas and will be helpful for reducing the mortality of cubs,younger than 1 month old,in captivity.

大熊猫母兽可根据幼仔的尖叫声辨别自己的后代

研究表明,群居哺乳动物具备通过叫声进行母幼识别的机制,而有关独栖动物的母幼识别机制鲜有研究。大熊猫(Ailuropoda melanoleuca)是典型的独栖动物,原始森林是保持野生大熊猫种群数量可持续发展的必要条件,其中的大型古树提供的育幼巢穴对大熊猫幼仔的存活至关重要。但是,近年来大型古树因受人为干扰而急剧减少,致使野生成年雌性大熊猫活动领域的重叠增大,在育幼期产仔大熊猫母兽对育幼巢穴的利用产生了竞争。大熊猫幼仔的体重约为成年大熊猫的0.1%,幼仔需要母兽高度关怀才能存活和成长。叫声是0-45日龄大熊猫幼仔向其母兽传递生理需求或所处状态的主要方式。然而,母兽能否根据幼仔的叫声识别自己的后代,目前尚无定论。本研究以274条大熊猫幼仔的尖叫声为例,首先对其进行个体独特性分析,然后通过叫声回放以及母兽对所回放的两种叫声的行为反应,验证大熊猫母兽能否辨别出其亲生幼仔。结果发现,尖叫声的17个声学参数中有14个具有潜在的个体判别能力(PIC>1);进一步的判别分析结果显示,基于这17个声学参数,78.5%的尖叫声被正确分配到对应的幼仔;叫声回放实验的结果显示,母兽在行为上更倾向其亲生幼仔的尖叫声(P=0.008)。我们的结果表明尖叫声可以编码大熊猫幼仔的身份信息,且圈养大熊猫母兽通过该叫声能辨别亲生和非亲生后代。本研究结果为大熊猫的迁地保护和圈养大熊猫繁育工作提供了理论依据,对人工繁育大熊猫幼仔存活率具有重要意义。

Highly Emissive Luminogens in Both Solution and Aggregate States

Organic light-emitting materials have attracted considerable attention because of their promising applications in diverse areas.Most fluorophores emit brightly in either dilute solutions or aggregate states;the former generally suffer from aggregation-caused quenching problem,and the latter encounter intensity loss at low concentrations.Herein,we propose a new strategy to overcome these dilemmas by balancing the planar and distorted structures of terphenyl-based luminogens and obtain three luminogens,2PB-AC,2Me2PB-AC,and 2T2PB-AC,with bright emission in both solution and aggregate states.Among them,2PB-AC shows absolute photoluminescence quantum yields(ФPL)higher than 90%in both tetrahydrofuran solution(90.2%)and aggregate states(92.7%for powder and 95.3%for crystal).Thus,2PB-AC could be an efficient probe to realize dual-channel explosive detection in both solution and aggregate states.Moreover,it could be used to image live-cell lipid droplets at a wide range of concentrations.In addition,benefiting from its thermodynamically favorable intersystem crossing process,2Me2PB-AC could be doped in polymethyl methacrylate matrix to provide efficient room-temperature phosphorescence.Thus,this work provides a feasible strategy for the design of luminogens with highly efficient emission in both solution and aggregate states,greatly facilitating and broadening their practical applications.

四川卧龙国家级自然保护区多空间尺度下绿尾虹雉的生境选择

动物的生境选择具有空间尺度依赖性,在不同空间尺度上影响生境选择的环境因素有所不同。研究不同空间尺度下动物生境选择的关键影响因子及其季节性变化,对于全面了解物种的生境资源需求和开展生境保护具有重要意义。绿尾虹雉(Lophophoruslhuysii)是中国特有的高山雉类,国家一级重点保护野生动物,具有极高的保护价值。然而,目前尚未对其不同尺度和时期的生境选择进行过探究。本研究于2019年10月至2020年10月,在四川卧龙国家级自然保护区的羊角湾、魏家沟和文扎都3个区域共布设15条样线、303个样方,并结合红外相机监测(176个红外相机位点),对保护区内绿尾虹雉种群的生境利用状况进行了调查,使用主成分分析和逻辑斯蒂回归模型分别从景观和微生境两个尺度对繁殖期(3-8月)和非繁殖期(9月至翌年2月)的生境选择模式进行了分析。结果显示,在景观尺度上,在繁殖期和非繁殖期都显著偏好海拔较高(3,700-4,300 m)、坡度较小(27°-33°)、靠近阳坡、草甸和流石滩比例较高而森林和灌丛比例较低的生境。在微生境尺度上,绿尾虹雉在繁殖期显著偏好岩石盖度较高的生境;而非繁殖期则显著偏好草本盖度较高、灌木盖度和落叶盖度较低的生境。研究表明,绿尾虹雉在景观和微生境尺度上均对生境有明显的选择性,并且其微生境选择还存在季节性变化,反映了该物种在生活史不同阶段具有不同的资源需求。本研究丰富了绿尾虹雉的基础生态学信息,为卧龙及其他自然保护区绿尾虹雉的生境管理和种群保护工作提供了参考。

四川卧龙国家级自然保护区三种高山同域鸡形目鸟类的时空生态位比较

高海拔山区气候条件恶劣,资源匮乏,探究同域分布的近缘物种如何利用有限的资源以实现稳定共存,对于了解高山生态系统生物多样性格局的形成和维持机制具有重要意义。鸡形目鸟类飞行能力弱,属于典型的地栖物种,生态位空间相对狭窄,可能面临更高的种间竞争压力。本研究旨在比较几种同域分布的鸡形目鸟类的时空生态位,为了解高山生态系统同域物种的共存机制提供新的研究案例。2020年4-9月,研究人员在四川卧龙国家级自然保护区海拔3,300-4,200m的高山区域进行了野外调查,通过样线法和样方法对鸡形目鸟类群落优势物种绿尾虹雉(Lophophorus lhuysii)、雉鹑(Tetraophasis obscurus)和雪鹑(Lerwalerwa)繁殖期的微生境进行调查,使用红外相机对其活动节律进行监测,并运用核密度估计法从微生境利用和日活动节律两个生态维度进行了种间生态位比较。结果显示,雪鹑在微生境利用和日活动节律上均与其他两个物种存在显著差异。绿尾虹雉与雉鹑在微生境的利用上具有相似偏好;但绿尾虹雉的早活动高峰晚于雉鹑,晚活动高峰早于雉鹑,表现出显著的种间日活动节律差异;然而,整合两个维度后,绿尾虹雉和雉鹑的整体生态位仍然高度重叠,没有显著分化。本研究表明高山鸡形目物种间的生态位分化体现于多个不同的生态维度,并且不同物种之间的分化方式有所差异。在空间和时间生态位上的显著分化使雪鹑与同域物种间的竞争压力相对较小,有利于其实现稳定共存。而绿尾虹雉与雉鹑的整体生态位高度重叠,建议进一步对其食性开展研究,探讨营养生态位上的潜在种间分化。

Natural variations in grain length 10(GL10)regulate rice grain size

Grain size is an important determinant of grain weight and yield in rice.Although several genes related to grain size have been identified,natural variations in these genes that affect grain size are poorly characterized.Here,we describe the grain length QTL GL10,encoding MADS56,which positively regulates grain length and grain weight.A natural allelic variation of NIL-gl10,containing an~1.0-kb deletion in the first exon that abolishes its transcription,results in shorter grain length,lower grain weight and delayed flowering in gl10 plants.The knockout of GL10 in the HJX74 background leads to grain phenotypes similar to that of NIL-gl10,while overexpression of GL10 results in increased grain length and weight and earlier heading date.GL10 regulates grain length by promoting greater longitudinal cell growth in the grain glume.Additionally,GL10 participates in the regulation of gibberellic acid(GA)signaling pathway genes in young panicle tissues.Analysis of GL10 haplotypes shows obvious divergence between the japonica and indica lineages.Our findings reveal an allelic variation of GL10 that may explain differences in grain length among modern cultivars and could be used to breed rice varieties with optimized grain shape.