mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
丙草胺对水稻生理生化特性的影响

近年来,除草剂对作物的药害时有发生,严重影响农业增产和农民增收.在除草剂药害症状出现之前,其对作物生理生化的影响即已存在,因此,研究施用除草剂后作物相关生理生化指标变化,将有助于预测潜在除草剂药害.丙草胺除草效果良好,已在水稻田得到广泛应用.但是,目前国内外对丙草胺的研究主要集中在其药效方面,其对水稻生理生化的影响却未见报道.作者针对丙草胺对水稻生理生化特性影响进行探讨,以期为丙草胺的合理施用提供理论依据.
内疚和羞耻关系研究进展及未来展望(综述)

内疚(guilt)(guilt在汉语中有不同的译法.如内疚、负疚感、负罪感、罪感等.为避免不同的译法可能产生的概念理解上的混淆,同时也为与"羞耻"一词相对应,本文沿用"内疚"的译法)和羞耻(shame)关系的研究是最近十多年来国外心理学界研究的热点课题.作为人类高度社会化的负性自我道德情感体验,内疚和羞耻既是个体对自身经历的不良事件进行评价和认知的产物,同时也是影响个体后续行为的重要因素,而且它们都与个体的身心健康和社会化的发展有着非常密切的关系.越来越多的研究揭示出这两者在内容特点上表现出很大的不同,特别是在概念界定、认知评价、情感体验、行为表现以及心理病理学等方面表现出巨大的差异性.但通过对这些研究的深入分析发现,关于内疚和羞耻的研究方法却有许多相似之处.总结和梳理内疚和羞耻研究在内容上的差异性和方法上的趋同性,对深入探讨两者错综复杂的关系具有重要的理论价值.
瑞香狼毒化学成分与抗肿瘤作用研究进展

瑞香狼毒(Stellera chamaejasme)为瑞香科狼毒属植物,又名红狼毒、棉大戟、断肠草等,为中药狼毒之正品,有毒,用药部位为根,性味苦平,有逐水祛痰,破积杀虫之功效。主要分布于中国、俄罗斯、蒙古和朝鲜等国,在我国青海、甘肃、陕西、新疆、西藏、内蒙古等地资源丰富。现代药理学研究发现具有抗肿瘤、抗病毒、调节免疫等活性,最新研究还发现其具有抑菌、杀虫和抗癫痫作用,特别是抗HIV病毒作用。对瑞香狼毒进行更深入的研究,有助于促进瑞香狼毒药用资源的利用,寻找和开发新的抗肿瘤药物。本文对国内外瑞香狼毒化学成分及抗肿瘤活性研究的进展加以综述。
基于利益相关者的乡村旅游开发研究——以安徽省池州市为例

本文基于利益相关者理论,分析了乡村旅游开发中的主要利益相关者,并以安徽省池州市为例探讨了乡村旅游开发模式及其利益冲突,提出了乡村旅游开发利益协调对策.
高精尖探索铸就技术摇篮产学研联动发展镀膜产业——记中科院上海光机所光学薄膜技术研究与发展中心

中科院上海光机所光学薄膜技术研究与发展中心(以下简称薄膜中心)专门从事光学薄膜技术的研究与开发,其前身是1964年组建的、并集结了当时全国从事激光薄膜研制大部分骨干力量的上海光机所技术光学研究室"镀膜组".经过40多年的发展,薄膜中心在光学薄膜制备方面拥有雄厚的研究基础和完善的测试平台;特别是高性能、高损伤阈值激光薄膜的研究处于国内领先水平.在稳抓基础研究、完善镀膜工艺的同时,薄膜中心积极转化研究成果,推进薄膜产业化,特别是在1999年成立了薄膜事业部.该部目前已经实现了汽车车灯薄膜、强光防护滤光片、透明导电膜、紫外激光薄膜和高品质激光波长分离薄膜产品等多个系列薄膜产品和器件的量化生产.
杂交稻万金优133种植示范及栽培技术

根据揭西县部分山区乡镇的土质和气候特点,为了寻找适合这些地区推广种植的高产优质杂交水稻品种,我们在揭西县五云镇开展的田间种植示范表明,万金优133品种在产量、抗病性等方面表现十分突出,可在全县同类地区进行大面积推广种植.
第二讲——关于水

1 了解水的重要意义作为电镀的基本知识,为什么要先讲水呢?一、水是电镀液的主要组分.倘若有人问你电镀液有哪些组分,千万不要忘了一个最主要的组分--水.电镀几乎都是在水溶液中进行.尽管有非水溶液电镀的报道(如在甘油中镀铝,在二甲基亚砜中镀纳米半导体线,在乙酰胺-尿素-溴化钾熔体中镀半导体纳米合金),但均限于实验室研究,并无工业化应用.溶液由溶质和溶剂组成.
男性免疫性不育有关病因因素的研究进展

免疫因素是WHO男性不育标准化病因分类诊断之一.2000年WHO诊断标准为:性及射精功能正常,在至少一份精液标本中,混合抗球蛋白反应试验(MAR)或免疫珠试验有不少于50%活动精子表面被覆抗体[1].原因不明的不育夫妇中,约10%为免疫因素所致.不育男子中有6%-10%可在血或精液中查到抗精子抗体(anti-sperm antibody,AsAb).本文对免疫性不育机制的研究进展综述如下。
动力学荧光光度法测定人发中痕量镍

镍是人体的必需微量元素之一,在人体内参与一些酶的组成和代谢;镍能增强胰岛素分泌,有降低血糖作用;适量的镍能促进脱氧核糖核酸(DNA)和核糖核酸(RNA)正常生理功能的发挥,但若量过多,会使RNA复制失真,DNA受到损伤,引起突变,甚至致癌.因此，研究人体现人镍含量的测定，具有重要的意义。测定镍最常用的方法是原子吸收光谱法和丁二酮肟光度法、动力学光度法等。本试验在近中性介质中，痕量镍对过氧化氢氧化曙红Y反应具有很强的催化作用，采用更灵敏的荧光法检测，建立了动力学荧光光度法测定人发中痕量镍。
急性肾损伤与急性肺损伤

多器官功能衰竭患者损伤脏器之间的关系复杂,单一器官的损伤可对不相邻器官如肺、消化道和肾脏产生明显影响.越来越多的临床事件证实急性肾损伤(acute kidney injury,AKI)常合并急性肺损伤(acute lung injury,ALI).本文就两者之间的双向作用(ALI和机械通气对.肾脏的影响、AKI导致的肺脏结局以及肺肾之间的不利交叉干扰)作一综述.
湘珠牌水稻专用肥在湘南灰泥田上的施用效果

采用田间试验的方法,研究了湘珠牌水稻专用肥在湘南灰泥田上的施用效果.试验设置CK(不施肥)、NPK(氮磷钾)、HNPK(高氮磷钾养分含量复合肥)、DNPK(湘珠牌水稻专用肥,固定的氮磷钾配比)4个处理.结果表明:(1)施用湘珠牌水稻专用肥能够促进水稻分蘖,增加水稻千粒重,提高结实率;(2)施用湘珠牌水稻专用肥能够提高水稻产量.早稻产量6567.0kg/hm~2,比单质化肥NPK处理增产2.1%,晚稻8 000 kg/hm~2,比单质化肥NPK处理增产11.1%;(3)在湘南灰泥田上施用湘珠牌水稻专用肥,能提高肥料利用率.早稻氮利用率为33.56%,比单质化肥NPK处理高3.08%;磷利用率为16.82%,比单质化肥NPK处理高1.49%;钾利用率为21.72%,比单质化肥NPK处理高7.79%.晚稻氮利用率为37.02%,比单质化肥NPK处理高3.11%;磷利用率为54.33%,比单质化肥NPK处理高3.76%;钾利用率为82.55%,比单质化肥NPK处理高53.79%.
稻糠在水稻栽培中的应用研究进展

综述了稻糠在水稻栽培中的除草、增肥、增产作用及效益.在分析国内外稻糠施用技术的基础上,提出稻糠在水稻栽培中的利用是我国绿色水稻栽培和改善生态环境的新途径,并提出我国在稻糠应用技术上至少在6个方面值得进一步研究:(1)不同温度、土壤类型条件下对稻糠的分解速度和分解产物的影响;(2)不同种类和品种的稻糠在除草、增肥和增产上的差异;(3)最佳用量稻糠对米质的影响大小和作用机理;(4)施用稻糠对土壤结构和土壤环境的影响;(5)稻糠与其它有机无机肥配合施用技术;(6)不同栽培和耕作方式条件下稻糠的配套施用技术.
填充型高产烟叶开发品种的筛选

初步从国内外的一些主要多叶品种中筛选出了2个产量高、综合性状优良、适合作为填充型烟叶的品种:CY9504和YH05.另外.HT61产量最高,达265 kg/667m~2.但由于该品种叶片烘烤水平没有达到该品种要求,明年可继续进行示范试验,该品种挖掘潜力较大.
垄作宽窄行栽培对夏玉米生理指标及产量构成因子的影响

利用中早熟品种浚单22,研究了垄作宽窄行栽培对夏玉米生理指标及产量构成因子的影响.结果表明,与传统平作等行距栽培相比,垄作宽窄行栽培有利于夏玉米根系的生长和干物质的积累,株高增高,叶面积系数前期增长快,后期下降慢,叶面积高值持续期长,干物质积累快,生物产量高,穗粒数多,千粒重高,产量性状明显改善,增产显著.
保得微生物土壤接种剂在烟草上的田间试验总结

通过田间试验和实验室检测得出:保得微生物接种剂能促进烟草植株的前期生长,提高烟叶产量,并能改善土壤环境,提高肥料利用率,而且90 g/hm~2的施用量比60 g/hm~2的施用量更能使烟株长势旺盛,产量更高.表明在一定范围内保得微生物接种剂对烟株生长的促进作用随微生物肥料施用量的增加而变大.
不同种类蔬菜硝酸盐含量及其与土壤肥力因素的关系

通过对长沙市东湖村(菜园土壤母质为第四纪红土)和杉木村(菜园土壤母质为河流冲积物)两个露天蔬菜生产基地的6种86个春夏季蔬菜进行硝酸盐含量的测定并与对应的菜园土壤8个肥力指标间进行了逐步回归分析.结果表明,两种菜园土上6种蔬菜硝酸盐的含量和其含量的变异系数均表现为叶菜类＞瓜果茄豆类,且叶菜类蔬菜硝酸盐平均含量是瓜果茄豆类的3.3倍;6种蔬菜中,除苋菜外,其它如空心菜、青椒、红茄子等5种蔬菜硝酸盐含量是冲积菜园土＞红菜园土.6种蔬菜中,其中叶菜类蔬菜硝酸盐达高度污染水平的平均占57%以上,达严重污染水平的占14%以上;其它类蔬菜硝酸盐达中度污染水平的平均低于50%.6种蔬菜硝酸盐含量与对应的土壤肥力指标之间均能够建立回归方程,其相关系数均达显著以上正相关.土壤硝态氮、速效磷和全钾含量是影响蔬菜硝酸盐含量的土壤肥力因素,其中土壤硝态氮含量又是主要因素.
常用永磁材料及其应用基本知识讲座第八讲如何使永磁体老化(磁损失)尽量小

1 引言　　钡锶铁氧体、钐钴和钕铁硼,这三类永磁材料具有共同的本质--磁晶各向异性常数K是主导它们的磁化过程和反磁化过程的决定因素.
中国粘结NdFeB磁体行业协会2008会议简讯

按照市场规律，在没有通货膨胀、原材料价格波动的正常年份，磁体随用量的逐年增大，其价格每年应降低2-3%。而MQ磁粉售价自1990年代中期即固定为$34/kg，这样留给磁体厂家的利润就非常有限。有时甚至没有利润。MQI因拥有专利垄断而保持其在此领域的优势。MQI从磁粉销售中获得暴利，却将一大堆困难转嫁给了用户，这种情况极大地伤害了粘结磁体产业的正常发展。新世纪伊始粘结NdFeB磁体厂家即陷入艰难的境地：他们既要面对MQ粉固定的高价，又须面对磁体市场永恒的降价压力。这种进退维谷的两难处境他们必需应对，一些人认识到问题的严重性后，选择了放弃，或寻找其它业务替代生产粘结NdFeB磁体，或寻找另外的货源取代MQ磁粉，以便彻底摆脱MQI的控制。
Study of microstructures and properties for girth welding of domestic X70 pipeline steels

With the development of domestic pipeline steels, it is necessary to develop suitable welding technology which can improve the properties of the welded pipeline. In this paper, the microstructures and mechanical properties of domestic X70 pipeline steels and welded joints are discussed. The welding consumables of BOHLER E6010 and HOBART 81N1 are matched for girth welding. The following characteristics in heat-affected zone(HAZ) are indicated that microstructures of intercritical HAZ(ICHAZ) is finer and more uniform, the grain sizes of fine-grain HAZ(FGHAZ) and subcritical HAZ(SCHAZ) are smaller than that of coarse-grain HAZ(CGHAZ). The hardness, tensile strength and toughness of welded joints come up to the standard. The micrographs of impact specimens in welded joints are cleavage, quasi-cleavage and dimple which shows there is typical ductile rupture.
Impact pressuring diffusion bonding of TA17 to 0Cr18Ni9Ti

Impact pressuring diffusion bonding tests were carried out to produce joint between TA17 titanium alloy and 0Cr18Ni9Ti stainless steel. The reaction products and microstructure near the bonding interface were analyzed. The diffusion of Fe, Cr, Ni and Ti in the bond was revealed by energy dispersive spectroscopy. A number of phases, such as β-Ti, Fe_2Ti and σ phases were identified by X-ray diffraction. It was concluded that the bonded joint broke in the region somewhere between Fe-Ti intermetallics and β-Ti during tensile loading. The relationship between bonding parameters and tensile strength of the joint was also determined experimentally, and the optimum time of bonding was only 220 s with 293 MPa joint strength.
土壤中中性脂肪酶菌株分离选育及其酶学性质研究

脂肪酶是用来催化酯类化合物的分解、合成和酯交换的酶,具有高度的化学选择性和立体异构性,可广泛应用于轻纺、皮革、化妆品、洗涤剂、医药以及食品等领域。随着研究的深入,脂肪酶还被应用于石油污染土壤的生物修复、柴油替代品的合成、旧报纸的脱墨、含油污水的处理等方面,可见脂肪酶在环保领域也具有良好的应用前景。
肥料氮和土壤氮对烤烟氮素吸收和烟碱合成的影响

烤烟是我国重要的经济作物,氮素营养对烟草的产量和质量起着重要的作用。烟碱含量是评价烟叶质量的关键指标之一,有许多因素影响烟叶中烟碱含量。比如降雨、外界温度、光照、土壤特性和栽培措施。在可控制因素中,氮素营养对调控烟碱含量显得尤为重。肥料氮和土壤氮作为烤烟氮素的两种主要来源,其对烤烟氮素营养和烟碱合成影响如何?关于这方面的研究甚少。目前,许多研究表明,农田肥料氮过多施用造成作物品质下降、土壤中肥料氮素残留过多乃至地下水体污染等问题。为此,选择了种烟大省———云南省的玉溪地区作为试验点,并用15N示踪技术在烤烟全生育期进行追踪试验,从而系统研究肥料氮和土壤氮在烤烟各个生育时期各个器官中的分布以及其对烟碱合成的贡献,为烤烟生产中氮肥实施提供一定的合理依据.
中东部大范围强降水 地震灾区阴雨天气多

5月,全国平均气温为16.6℃,较常年同期(15.6℃)偏高1.0℃,为历史同期第三高。新疆月平均气温为1951年以来历史同期最高值,湖北、甘肃、青海为第三高。全国平均月降水量为66.0mm,接近常年同期(66.7mm)。黑龙江月降水量为1951年以来历史同期第二多;宁夏、重庆为历史同期最少.5月份我国主要天气乞候事件有:下旬中东部地区出现大范围强降水,局地受灾重;南主部分地区受协雨大风、冰雹等强对流天气袭击，地震灾区震后阴雨天气多，给救灾带来不利影响，西北东部及内蒙古等地干持续；北方出现4次沙尘天气过程。
冲绳海槽中部过去15ka来浮游植物生产力和种群结构变化的生物标志物重建

生物标志物已经被广泛应用于重建海洋浮游植物生产力和种群结构变化.本文将这种方法应用于冲绳海槽中部来重建冰消期至全新世浮游植物生产力和种群结构变化生物标志物总含量的变化表明冰消期海洋生产力高于全新世;而生物标志物的相对比例变化显示浮游植物种群结构发生了改变,冰消期期间颗石藻的相对比例下降,而甲藻和硅藻升高.冰消期初级生产力的增加与冬季季风加强有关.另外,相对低的海平面也会造成陆源营养盐输送增加.陆源生物标志物(长链偶数正构醇)含量的增加也证明了陆源物质输送的增加.同时,冰消期期间营养盐输送的变化也改变了浮游植物的种群结构.
血必净治疗乙型肝炎相关性肾炎合并蜂窝织炎一例

1病例简介患者,男,25岁,反复颜面、下肢水肿4年余,3d前无明显诱因再次出现颜面、下肢水肿,伴左腹股沟区红肿热痛,不能行走,并有恶寒、发热等症状,肾内科予激素、抗感染等治疗,症状未能缓解,行简单切开引流术后,症状稍改善,但脓性分泌物较多,且持续高热不退,于2007-04-14转我科治疗。患者2003年肾穿刺病理示:乙型肝炎病毒相关性肾小球肾炎,局灶性系膜增生性肾小球肾炎;肝穿刺病理示:乙型肝炎病毒携带者肝组织轻微病变,诊断为:乙型肝炎相关性肾炎。查体:急性面容,全身皮肤、黏膜无黄染、淤斑,双下肺呼吸音弱,未闻及干性啰音。T38.5℃,心率145次/min,律齐;腹平软,无压痛、反跳痛,移动性浊音阴性,双肾未触及,双肾区无明显叩痛,双下肢肌肉萎缩明显并呈重度凹陷性水肿,左下肢皮肤发红,皮温稍高,双腹股沟处见散在皮藓、皮损,左侧大腿内侧部有7cm×6cm呈红色稍高于皮肤的大块片状皮损(见图1),皮温增高,触痛明显,有捻发音,神经系统病理征未引出。
心肺复苏后微创手术救治脑室出血成功一例

1病例简介患者,女,64岁,因“突发性意识不清1h”入院。患者既往有高血压病,糖尿病病史。行颅脑CT示:双侧脑室、第三和第四脑室出血,第三、四脑室铸型。诊断:脑室出血,高血压病3级(极高危),2型糖尿病。入病房时,患者突然呼吸、心跳停止,立即气管插管,心肺复苏,呼吸机辅助呼吸,同时给予降颅压、营养神经细胞等药物治疗,心跳恢复。随后经家属同意,在气管插管、呼吸机辅助呼吸情况下,行床旁微创单侧脑室引流、腰椎穿刺脑脊液等量置换术,尿激酶2~5万U注入脑室,关闭3~4h开放引流,1次/d;隔日腰穿10~15万U尿激酶加入到40ml0.9%氯化钠溶液中进行脑脊液等量置换;辅以气管切开、呼吸机辅助呼吸、控制血压、冬眠、脱水、营养支持、防治并发症等综合治疗。第8天患者苏醒,问答合理,1个月后患者出院,行颅脑CT示脑室血肿完全吸收,此时患者肢体活动自如。随访3年,中途曾出现脑干血栓形成。目前患者意识清,远、近期记忆均正常,可适当自行活动及功能锻炼。
Interaction of the Arabidopsis UV-B-Specific Signaling Component UVR8 with Chromatin

Arabidopsis UV RESISTANCE LOCUS8 (UVR8) is a UV-B-specific signaling component that regulates expression of a range of genes concerned with UV protection. Here, we investigate the interaction of UVR8 with chromatin. Using antibodies specific to UVR8 in chromatin immunoprecipitation (ChIP) assays with wild-type plants, we show that native UVR8 binds to chromatin in vivo. Similar experiments using an anti-GFP antibody with plants expressing a GFP–UVR8 fusion show that UVR8 associates with a relatively small region of chromatin containing the HY5 gene. UVR8 interacts with chromatin containing the promoter regions of other genes, but not with all the genes it regulates. UV-B is not required for the interaction of UVR8 with chromatin because association with several gene loci is observed in the absence of UV-B. Pull-down assays demonstrate that UVR8 associates with histones in vivo and competition experiments indicate that the interaction is preferentially with histone H2B. ChIP experiments using antibodies that recognize specific histone modifications indicate that the UV-B-stimulated transcription of some genes may be correlated with histone modification. In particular, the ELIP1 promoter showed a significant enrichment of diacetyl histone H3 (K9/K14) following UV-B exposure. These findings increase understanding of the interaction of the key UV-B-specific regulator UVR8 with chromatin.
Dual Functions of Phospholipase D1 in Plant Response to Drought

Phospholipase D1 (PLD1) has been shown to mediate the abscisic acid regulation of stomatal movements. Arabidopsis plants deficient in PLD1 increased, whereas PLD1-overexpressing tobacco decreased, transpirational water loss. In the early stage of drought, the decrease in water loss was associated with a rapid stomatal closure caused by a high level of PLD in PLD1-overexpressing plants. However, in the late stage of drought, the overexpressing plants displayed more susceptibility to drought than control plants. PLD1 activity in the overexpressing plants was much higher than that of control plants in which drought also induced an increase in PLD1 activity. The high level of PLD1 activity was correlated to membrane degradation in late stages of drought, as demonstrated by ionic leakage and lipid peroxidation. These findings indicate that a high level of PLD1 expression has different effects on plant response to water deficits. It promotes stomatal closure at earlier stages, but disrupts membranes in prolonged drought stress. These findings are discussed in relation to the understanding of PLD functions and potential applications.
Ethylene Controls Autophosphorylation of the Histidine Kinase Domain in Ethylene Receptor ETR1

Perception of the phytohormone ethylene is accomplished by a small family of integral membrane receptors. In Arabidopsis, five ethylene receptor proteins are known, including ethylene resistant 1 (ETR1). The hydrophobic amino-terminal domain of these receptors contains the ethylene-binding site while the carboxyl-terminal part consists of a histidine kinase domain and a response regulator domain, which are well known elements found in bacterial two-component signaling. The soluble membrane-extrinsic carboxyl-terminal part of the receptor, which is likely to play an important role in signal transduction, showed intrinsic kinase activity when expressed and purified on its own. However, a correlation between signal input and autokinase activity was not established in these studies, as receptors were missing the transmembrane amino-terminal sensor domain. Thus, it is still unclear whether autophosphorylation occurs in response to perception of the ethylene signal. Here, we report on autophosphorylation studies of purified full-length ETR1. Autokinase activity of the purified receptor is controlled by ethylene or by ethylene agonists like the -acceptor compound cyanide. In fact, both signal molecules were able to completely turn off the intrinsic kinase activity. Furthermore, the observed inhibition of autophosphorylation in ETR1 by both molecules could be prevented when the ethylene antagonist 1-methyl-cyclopropene (MCP) was applied.
Disruptions in AUX1-Dependent Auxin Influx Alter Hypocotyl Phototropism in Arabidopsis

Phototropism represents a differential growth response by which plant organs can respond adaptively to changes in the direction of incident light to optimize leaf/stem positioning for photosynthetic light capture and root growth orientation for water/nutrient acquisition. Studies over the past few years have identified a number of components in the signaling pathway(s) leading to development of phototropic curvatures in hypocotyls. These include the phototropin photoreceptors (phot1 and phot2) that perceive directional blue-light (BL) cues and then stimulate signaling, leading to relocalization of the plant hormone auxin, as well as the auxin response factor NPH4/ARF7 that responds to changes in local auxin concentrations to directly mediate expression of genes likely encoding proteins necessary for development of phototropic curvatures. While null mutations in NPH4/ARF7 condition an aphototropic response to unidirectional BL, seedlings carrying the same mutations recover BL-dependent phototropic responsiveness if co-irradiated with red light (RL) or pre-treated with either ethylene. In the present study, we identify second-site enhancer mutations in the nph4 background that abrogate these recovery responses. One of these mutations—map1 (modifier of arf7 phenotypes 1)—was found to represent a missense allele of AUX1—a gene encoding a high-affinity auxin influx carrier previously associated with a number of root responses. Pharmocological studies and analyses of additional aux1 mutants confirmed that AUX1 functions as a modulator of hypocotyl phototropism. Moreover, we have found that the strength of dependence of hypocotyl phototropism on AUX1-mediated auxin influx is directly related to the auxin responsiveness of the seedling in question.
A Rice Phytochrome A in Arabidopsis: The Role of the N-terminus under red and far-red light

The phytochrome (phy)A and phyB photoreceptors mediate three photobiological response modes in plants; whereas phyA can mediate the very-low-fluence response (VLFR), the high-irradiance response (HIR) and, to some extent, the low fluence response (LFR), phyB and other type II phytochromes only mediate the LFR. To investigate to what level a rice phyA can complement for Arabidopsis phyA or phyB function and to evaluate the role of the serine residues in the first 20 amino acids of the N-terminus of phyA, we examined VLFR, LFR, and HIR responses in phyB and phyAphyB mutant plants transformed with rice PHYA cDNA or a mutant rice PHYA cDNA in which the first 10 serine residues were mutated to alanines (phyA SA). Utilizing mutants without endogenous phyB allowed the evaluation of red-light-derived responses sensed by the rice phyA. In summary, the WT rice phyA could complement VLFR and LFR responses such as inhibition of hypocotyl elongation under pulses of FR or continuous R light, induction of flowering and leaf expansion, whereas the phyA SA was more specific for HIR responses (e.g. inhibition of hypocotyl elongation and anthocyanin accumulation under continuous far-red light). As the N-terminal serines can no longer be phosphorylated in the phyA SA mutant, this suggests a role for phosphorylation discriminating between the different phyA-dependent responses. The efficacy of the rice phyA expressed in Arabidopsis was dependent upon the developmental age of the plants analyzed and on the physiological response, suggesting a stage-dependent downstream modulation of phytochrome signaling.
Targeting of Pollen Tubes to Ovules Is Dependent on Nitric Oxide (NO) Signaling

The guidance signals that drive pollen tube navigation inside the pistil and micropyle targeting are still, to a great extent, unknown. Previous studies in vitro showed that nitric oxide (NO) works as a negative chemotropic cue for pollen tube growth in lily (Lilium longiflorum). Furthermore, Arabidopsis thaliana Atnos1 mutant plants, which show defective NO production, have reduced fertility. Here, we focus in the role of NO in the process of pollen–pistil communication, using Arabidopsis in-vivo and lily semi-vivo assays. Cross-pollination between wild-type and Atnos1 plants shows that the mutation affects the pistil tissues in a way that is compatible with abnormal pollen tube guidance. Moreover, DAF-2DA staining for NO in kanadi floral mutants showed the presence of NO in an asymmetric restricted area around the micropyle. The pollen–pistil interaction transcriptome indicates a time-course-specific modulation of transcripts of AtNOS1 and two Nitrate Reductases (nr1 and nr2), which collectively are thought to trigger a putative NO signaling pathway. Semi-vivo assays with isolated ovules and lily pollen further showed that NO is necessary for micropyle targeting to occur. This evidence is supported by CPTIO treatment with subsequent formation of balloon tips in pollen tubes facing ovules. Activation of calcium influx in pollen tubes partially rescued normal pollen tube morphology, suggesting that this pathway is also dependent on Ca~(2+) signaling. A role of NO in modulating Ca~(2+) signaling was further substantiated by direct imaging the cytosolic free Ca~(2+) concentration during NO-induced re-orientation, where two peaks of Ca~(2+) occur—one during the slowdown/stop response, the second during re-orientation and growth resumption. Taken together, these results provide evidence for the participation of NO signaling events during pollen–pistil interaction. Of special relevance, NO seems to directly affect the targeting of pollen tubes to the ovule's micropyle by modulating the action of its diffusible factors.
SWI1 Is Required for Meiotic Chromosome Remodeling Events

The Arabidopsis dsy10 mutant was previously identified as being defective in the synapsis of meiotic chromosomes resulting in male and female sterility. We report here the molecular analysis of the mutation and show that it represents a T-DNA insertion in the third exon of the SWI1 gene. Four mutations have now been identified in SWI1, several of which exhibit different phenotypes. For example, the swi1-1 and dyad mutations only affect meiosis in megasporocytes, while the swi1-2 and dsy10 mutations block both male and female meiosis. Furthermore, as part of a detailed cytological characterization of dsy10 meiocytes, we identified several differences during male meiosis between the swi1-2 and dys10 mutants, including variations in the formation of axial elements, the distribution of cohesin proteins and the timing of the premature loss of sister chromatid cohesion. We demonstrate that dsy10 represents a complete loss-of-function mutation, while a truncated form of SWI1 is expressed during meiosis in swi1-2 plants. We further show that dys10 meiocytes exhibit alterations in modified histone patterns, including acetylated histone H3 and dimethylated histone H3-Lysine 4.
Regulation of Arabidopsis Early Anther Development by the Mitogen-Activated Protein Kinases, MPK3 and MPK6, and the ERECTA and Related Receptor-Like Kinases

Mitogen-activated protein kinase (MAPK) and leucine-rich repeat receptor-like kinase (LRR-RLK) signaling pathways have been shown to regulate diverse aspects of plant growth and development. In Arabidopsis, proper anther development relies on intercellular communication to coordinate cell proliferation and differentiation. Two closely related genes encoding MAPKs, MPK3 and MPK6, function redundantly in regulating stomatal patterning. Although the mpk6 mutant has reduced fertility, the function of MPK3 and MPK6 in anther development has not been characterized. Similarly, the ERECTA (ER), ERECTA-LIKE1 (ERL1) and ERL2 genes encoding LRR-RLKs function together to direct stomatal cell fate specification and the er-105 erl1-2 erl2-1 triple mutant is sterile. Because the mpk3 mpk6 double null mutant is embryo lethal, anther development was characterized in the viable mpk3/+ mpk6/– and er-105 erl1-2 erl2-1 mutants. We found that both mutant anthers usually fail to form one or more of the four anther lobes, with the er-105 erl1-2 erl2-1 triple mutant exhibiting more severe phenotypes than those of the mpk3/+ mpk6/– mutant. The somatic cell layers of the differentiated mutant lobes appeared larger and more disorganized than that of wild-type. In addition, the er-105 erl1-2 erl2-1 triple mutant has a reduced number of stamens, the majority of which possess completely undifferentiated or under-differentiated anthers. Furthermore, sometimes, the mpk3/+ mpk6/– mutant anthers do not dehisce, and the er-105 erl1-2 erl2-1 anthers were not observed to dehisce. Therefore, our results indicate that both ER/ERL1/ERL2 and MPK3/MPK6 play important roles in normal anther lobe formation and anther cell differentiation. The close functional relationship between these genes in other developmental processes and the similarities in anther developmental phenotypes of the two types of mutants reported here further suggest the possibility that these genes might also function in the same pathway to regulate anther cell division and differentiation.
OsWRKY62 is a Negative Regulator of Basal and Xa21-Mediated Defense against Xanthomonas oryzae pv. oryzae in Rice

The rice Xa21 gene, which confers resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), encodes a receptor-like kinase. Few components involved in transducing the Xa21-mediated defense response have yet been identified. Here, we report that XA21 binds to a WRKY transcription factor, called OsWRKY62. The OsWRKY62 gene encodes two splice variants (OsWRKY62.1 and OsWRKY62.2). OsWRKY62.1:smGFP2 and OsWRKY62.2:smGFP2 fusion proteins partially localize to the nucleus. Transgenic plants overexpressing OsWRKY62.1 are compromised in basal defense and Xa21-mediated resistance to Xoo. Furthermore, overexpression of OsWRKY62.1 suppresses the activation of defense-related genes. These results imply that OsWRKY62 functions as a negative regulator of innate immunity in rice, and serves as a critical mediator of both basal and race-specific defense responses.
Nuclear Trafficking During Plant Innate Immunity

Land plants possess innate immune systems that can control resistance against pathogen infection. Conceptually, there are two branches of the plant innate immune system. One branch recognizes conserved features of microbial pathogens, while a second branch specifically detects the presence of pathogen effector proteins by plant resistance (R) genes. Innate immunity controlled by plant R genes is called effector-triggered immunity. Although R genes can recognize all classes of plant pathogens, the majority can be grouped into one large family, encoding proteins with a nucleotide binding site and C-terminal leucine rich repeat domains. Despite the importance and number of R genes present in plants, we are just beginning to decipher the signaling events required to initiate defense responses. Recent exciting discoveries have implicated dynamic nuclear trafficking of plant R proteins to achieve effector-triggered immunity. Furthermore, there are several additional lines of evidence implicating nucleo-cyctoplasmic trafficking in plant disease resistance, as mutations in nucleoporins and importins can compromise resistance signaling. Taken together, these data illustrate the importance of nuclear trafficking in the manifestation of disease resistance mediated by R genes.