Fabrication and Characterisation of Novel Natural Lycopodium clavatum Sporopollenin Microcapsules Loaded In-Situ with Nano-Magnetic Humic Acid-Metal Complexes

Sporopollenin exines microcapsules, derived from the naturally occurring spores of Lycopodium clavatum, have been loaded in-situ with humic acid sodium salt-Zinc (HA-Zn) complex. The chemical treatment method utilised to prepare the sporopollenin microcapsules from raw spores was discussed and the resulted sporopollenin microcapsules were characterised using SEM, TGA and FTIR. Metal complexes of the sodium salt of humic acid and zinc ion were prepared using different protocols and in-situ loaded into the pre-treated sporopollenin microcapsules. The resulted complex was characterised before and after the encapsulation process using FTIR, TGA and XRD techniques. The morphology of the empty and loaded sporopollenin was not altered. Infrared spectroscopy revealed an increase in the absorption for COO– vibrations at 1583 and 1384 cm–1 in the FTIR spectra of HA-Zn complex compared to that of the original sodium salt of humic acid, indicative of bonding of the metal ions in hydrated form to the carboxyl or phenolic hydroxyl groups or both of the sodium humate molecules. TGA results of the HA-Zn complex loaded sporopollenin showed that around %15 of residual HA-Zn was successfully encapsulated indicative of the efficiency of the protocol used. We showed also that biodegradable magnetite nanoparticles can be surface modified with HA and encapsulated into sporopollenin. The resulted biosorbents microcapsules can be used for enhanced magnetic removal of either heavy metals or HA from different aqueous media.

Phenylpropanoid Derivatives Are Essential Components of Sporopollenin in Vascular Plants

The outer wall of pollen and spores,namely the exine,is composed of sporopollenin,which is highly resistant to chemical reagents and enzymes.In this study,we demonstrated that phenylpropanoid pathway derivatives are essential components of sporopollenin in seed plants.Spectral analyses showed that the autofluorescence of Lilium and Arabidopsis sporopollenin is similar to that of lignin.Thioacidolysis and NMR analyses of pollen from Lilium and Cryptomeria further revealed that the sporopollenin of seed plants contains phenylpropanoid derivatives,including p-hydroxybenzoate(p-BA),p-coumarate(p-CA),ferulate(FA),and lignin guaiacyl(G)units.The phenylpropanoid pathway is expressed in the tapetum in Arabidopsis,consistent with the fact that the sporopollenin precursor originates from the tapetum.Further germination and comet assays showed that this pathway plays an important role in protection of pollen against UV radiation.In the pteridophyte plant species Ophioglossum vulgatum and Lycopodium clavata,phenylpropanoid derivatives including p-BA and p-CA were also detected,but G units were not.Taken together,our results indicate that phenylpropanoid derivatives are essential for sporopollenin synthesis in vascular plants.In addition,sporopollenin autofluorescence spectra of bryophytes,such as Physcomitrella and Haplocladium,exhibit distinct characteristics compared with those of vascular plants,indicating the diversity of sporopollenin among land plants.

Cytochrome P450 mono-oxygenase CYP703A2 plays a central role in sporopollenin formation and ms5ms6 fertility in cotton

The double-recessive genic male-sterile(ms)line ms5 ms6 has been used to develop cotton(Gossypium hirsutum)hybrids for many years,but its molecular-genetic basis has remained unclear.Here,we identified the Ms5 and Ms6 loci through map-based cloning and confirmed their function in male sterility through CRISPR/Cas9 gene editing.Ms5 and Ms6 are highly expressed in stages 7–9 anthers and encode the cytochrome P450 mono-oxygenases CYP703A2-A and CYP703A2-D.The ms5 mutant carries a single-nucleotide C-to-T nonsense mutation leading to premature chain termination at amino acid 312(GhCYP703A2-A^(312aa)),and ms6 carries three nonsynonymous substitutions(D98E,E168K,and G198R)and a synonymous mutation(L11L).Enzyme assays showed that GhCYP703A2 proteins hydroxylate fatty acids,and the ms5(GhCYP703A2-A^(312aa))and ms6(GhCYP703A2-D^(D98E,E168K,G198R))mutant proteins have decreased enzyme activities.Biochemical and lipidomic analyses showed that in ms5 ms6 plants,C12–C18 free fatty acid and phospholipid levels are significantly elevated in stages 7–9 anthers,while stages 8–10 anthers lack sporopollenin fluorescence around the pollen,causing microspore degradation and male sterility.Overall,our characterization uncovered functions of GhCYP703A2 in sporopollenin formation and fertility,providing guidance for creating male-sterile lines to facilitate hybrid cotton production and therefore exploit heterosis for improvement of cotton.

VAMP726 from maize and Arabidopsis confers pollen resistance to heat and UV radiation by influencing lignin content of sporopollenin

Sporopollenin in the pollen cell wall protects male gametophytes from stresses.Phenylpropanoid derivatives,including guaiacyl(G)lignin units,are known to be structural components of sporopollenin,but the exact composition of sporopollenin remains to be fully resolved.We analyzed the phenylpropanoid derivatives in sporopollenin from maize and Arabidopsis by thioacidolysis coupled with nuclear magnetic resonance(NMR)and gas chromatography–mass spectrometry(GC–MS).The NMR and GC–MS results confirmed the presence of p-hydroxyphenyl(H),G,and syringyl(S)lignin units in sporopollenin from maize and Arabidopsis.Strikingly,H units account for the majority of lignin monomers in sporopollenin from these species.We next performed a genome-wide association study to explore the genetic basis of maize sporopollenin composition and identified a vesicle-associated membrane protein(ZmVAMP726)that is strongly associated with lignin monomer composition of maize sporopollenin.Genetic manipulation of VAMP726 affected not only lignin monomer composition in sporopollenin but also pollen resistance to heat and UV radiation in maize and Arabidopsis,indicating that VAMP726 is functionally conserved in monocot and dicot plants.Our work provides new insight into the lignin monomers that serve as structural components of sporopollenin and characterizes VAMP726,which affects sporopollenin composition and stress resistance in pollen.

Non-separated microspores 1 controls male meiotic callose deposition at the cell plate in rice

In flowering plants, callose(β-1,3-glucan) plays a vital role in pollen development, especially in the separation and development of microspores. However, the molecular mechanism of callose deposition during rice pollen development remains unclear. In this study, we isolated and characterized a novel rice pollen defective mutant, non-separated microspores 1(nsm1), which produced “dyad” or “tetrad” pollen grains. Cytological analysis indicated disrupted interstitial callose deposition at the cell plate of dyads and tetrads in nsm1 pollens. This disruption caused sporopollenin to be massively deposited outside of the junction where the interstitial callose wall connected with the peripheral callose wall, or unevenly distributed on the interstitial pollen primexine at the late meiosis stage. Consequently, an excess tectum-like layer was formed outside of the junction, connecting with the tectum of two microspores during later developmental stages, which prevented the separation of microspores. Additionally, in the linkage area, the tectum of two microspores gradually fused or degenerated, resulting in a decreased contact area between microspores and the anther locule. Therefore, the defect in callose deposition resulted in unsuccessful separation of microspores, abnormal deposition of pollen exine, and also affected the accumulation of materials in microspores, resulting in pollen semi-sterility. NSM1, encoding a callose synthase located in the Golgi body, is ubiquitously expressed in anthers with its peak expression at the young microspore stage. The in vitro enzyme activity assay confirmed that NSM1 possesses callose synthase activity, and the enzyme activity in the nsm1 mutants was significantly reduced.Phylogenetic analysis indicated that NSM1 and its orthologs play a highly conserved role in callose biosynthesis among plant species. Taken together, we propose that NSM1 plays an essential role in male meiotic callose synthesis and later pollen wall development.

北部湾盆地始新世古环境演化及沉积学意义

保存在地层中的孢粉化石是研究古植被、古气候变化的关键对象之一,对于重建古环境、预测烃源岩富集、指导油气勘探具有重要意义。本研究选取中国南海北部湾盆地乌石凹陷的WS-X1井、WS-X2井、海中凹陷的WZ-X3井、福山凹陷的JH-X4井始新世时期的孢粉进行分析,以揭示北部湾盆地始新世植被特征及其反映的古环境演化。研究共发现孢粉化石4大类共49个孢粉类型,以被子植物花粉占优势,其中栎粉Quercoidites(microhenrici+minutus)、三沟粉Tricolpopollenites、桤木粉Alnipollenites含量较高;裸子植物中以松粉Pinuspollenites为主;蕨类植物孢子以水龙骨单缝孢Polypodiaceaesporites、紫萁孢Osmundacidites为主;同时出现大量藻类,以盘星藻Pediastrum为主。4口井中,始新世亚热带类群丰富且花粉含量高,孢粉组合反映了北部湾盆地该时期发育以常绿栎类丰富为特征的林地,盆地低山地带发育常绿和落叶阔叶混交林为主的森林植被,林下为蕨类植被,指示了北部湾盆地始新世时期为温暖湿润的热带—亚热带气候。始新世早期分布的喜热植被较晚期更多,且在始新世晚期出现喜温的植被,推测始新世早期到晚期气候呈逐渐变凉的趋势。此外,孢粉组合中出现大量藻类,推测当时的沉积环境主要以湖泊和滨海的河流沼泽相为主。通过对北部湾盆地始新世时期的孢粉资料进行分析,为该盆地始新世时期的气候研究提供了更多依据。

生物基孢粉素微囊改性水性聚氨酯自消光涂层的制备及性能

采用物理共混法将孢粉素微囊(SEC)分散在水性聚氨酯(WPU)乳液中用于制备WPU自消光涂层,借助红外光谱仪(FTIR)、扫描电子显微镜(SEM)、热重分析(TG)和力学性能测试,结合表面水接触角和光泽度测试,从表面化学性质和物理结构特征两方面研究了SEC增强WPU的机理。SEM结果显示,SEC表面网孔结构与基体结合良好。其他测试分析表明,SEC/WPU复合材料的拉伸性能和热性能比SEC-0/WPU(纯WPU)更为优异,SEC-0/WPU的拉伸断裂强度为7.5 MPa,随着SEC的添加,样品的拉伸强度增加,SEC质量分数为0.46%时,SEC-0.46/WPU的拉伸强度达到最大(21.3 MPa)。质量保持率在70%时,样品的分解温度从320.6℃(SEC-0/WPU)提高到了333.4℃(SEC-0.84/WPU)。SEC的添加还降低了WPU软段的分解速率,增加了玻璃化转变温度(T_(g)),SEC-0/WPU的T_(g)仅为27.84℃,SEC-0.14/WPU达到了56.53℃。与SEC-0/WPU相比,SEC-0.84/WPU的表面水接触角增加了17.6°,表面光泽度从81.4 GU下降至6.8 GU,成功制备出拉伸性能和热性能优异的自消光涂层。

正交实验法优化5种不同花粉的孢粉素微胶囊载体的制备工艺研究

为优化5种不同花粉的孢粉素微胶囊载体的制备工艺。本研究以蛋白质去除率为指标,首先通过对磷酸体积分数、搅拌时间、搅拌温度3个因素进行单因素筛选,然后通过正交试验进行优化以得到孢粉素最佳制备工艺,并采用最大极差法对正交试验数据分析处理。结果表明,油菜花粉孢粉素的最佳制备条件为100℃、18 h和85%磷酸;茶花粉、向日葵花粉、玫瑰花粉和松花粉四种花粉孢粉素的最佳制备条件均为70℃、18 h和85%磷酸。但影响蛋白质去除率的主要因素不同,搅拌时间和搅拌温度是油菜花花粉蛋白质去除率的主要因素;搅拌温度是茶花花粉、向日葵花粉、玫瑰花花粉蛋白质去除率的最主要因素;搅拌时间是松花花粉蛋白质去除率的最主要因素。验证性试验按最优工艺制备3批样品,采用紫外可见分光光度(UV)法测定其蛋白质去除率,结果显示,油菜花花粉中蛋白质去除率为(90.62±0.091)%;茶花花粉中蛋白质去除率为(92.01±0.150)%;向日葵花粉中蛋白质去除率为(89.35±0.221)%;玫瑰花花粉中蛋白质去除率为(94.98±0.251)%;松花花粉中蛋白质去除率为(92.56±0.291)%。正交试验分析为不同花粉孢粉素的制备工艺提供了最优方案,为孢粉素微胶囊载体在药物递送系统的研究奠定了理论基础。

小麦生理型雄性不育花药绒毡层和孢粉素变化与RAFTIN1表达的关系

【目的】研究小麦生理型雄性不育花药绒毡层变化、孢粉素累积与RAFTIN1表达间的关系,为揭示小麦生理型雄性不育的机理奠定基础。【方法】以杀雄剂SQ-1诱导的生理型雄性不育系、质核互作遗传型雄性不育系,正常可育近等基因系为试材,通过石蜡切片、细胞荧光染色和荧光定量PCR技术,研究小孢子不同发育时期花药绒毡层的形态变化、孢粉素的累积及RAFTIN1的表达。【结果】单核期生理型不育系花药绒毡层提前降解,分泌孢粉素的含量降低,RAFTIN1提前高表达,使大量孢粉素转运至花粉壁层;二核期和三核期,生理型不育系绒毡层完全退化,停止分泌孢粉素,RAFTIN1呈现明显的下调表达模式。【结论】杀雄剂SQ-1诱导的小麦生理型雄性不育其败育机理与绒毡层的提前降解和定向转运孢粉素的RAFTIN1表达高低直接相关。

玉米基因雄性不育系(ms_2/ms_2)小孢子败育的细胞学研究

利用光镜和透射电镜对同一核背景的ms_2不育花药和正常可育花药进行了小孢子发育的细胞学比较观察。结果表明,ms_2不育花药小孢子在幼小孢子期至中小孢子期瓦解。小孢子从四分体释放后,原外壁上没有孢粉素沉积,花粉外壁不能发育。不育花药大多数绒毡层细胞在幼小孢子期显示出明显异常,表现为质体、线粒体等细胞器退化,内质网网络细而少,液泡膜内陷吞噬细胞质,细胞内侧没有乌氏体形成,细胞质内出现大量沉积有浓染颗粒的大的囊泡状结构,到中小孢于期绒毡层全面崩溃。本文还讨论了ms_2不育花药小孢于败育的可能原因。

孢粉稳定碳同位素研究进展

由于植物的光合作用途径不同,C3和C4植物的δ13C值有明显不同的分布范围,这可以用来研究环境的变化。花粉的碳同位素分析结果显示其δ13C值与植物的δ13C值变化规律一致,也能很好地反映植物的光合作用途径,进而间接反映其所处的气候环境条件。相比于植物体,化石花粉颗粒组成成分较单一,而其生成时间短,因而其碳同位素或许能较好地反映植物开花期时的环境条件,如雨水、大气CO2等的性质,为更精确的环境重建提供可能。初步的研究结果也显示花粉的δ13C值与开花期的温度存在线性关系。高精度结果的取得依赖于实验技术和仪器设备的改进,研究表明传统孢粉的醋酸酐处理过程中存在碳同位素污染,采用浓H2SO4浸泡可达到相同的去除纤维素的目的而避免污染。另外,通过对质谱仪的改进——装配旋转镍丝等进样系统(SWiM-IRMS),使实验所需的测试量大大减少,对单粒花粉进行测定也已经成为可能,但实验的精度还待进一步提高。

花粉中的孢粉素

花粉是植物繁殖细胞,由花粉壁和内含物( 营养物质)组成。孢粉素为花粉外壁的主要成分,由类胡萝卜素或胡萝卜素酯的氧化共聚物组成,是一种难于分解、耐高温、抗酸碱的物质,它使花粉外壁非常牢固,防护花粉营养物质不受外界干扰,且是自然界中石油、天然气的原始母质之一。

Plant Pollen Grains:A Move Towards Green Drug and Vaccine Delivery Systems

Pollen grains and plant spores have emerged as innovative biomaterials for various applications such as drug/vaccine delivery,catalyst support,and the removal of heavy metals.The natural microcapsules comprising spore shells and pollen grain are designed for protecting the genetic materials of plants from exterior impairments.Two layers make up the shell,the outer layer(exine)that comprised largely of sporopollenin,and the inner layer(intine)that built chiefly of cellulose.These microcapsule shells,namely hollow sporopollenin exine capsules have some salient features such as homogeneity in size,non-toxic nature,resilience to both alkalis and acids,and the potential to withstand at elevated temperatures;they have displayed promising potential for the microencapsulation and the controlled drug delivery/release.The important attribute of mucoadhesion to intestinal tissues can prolong the interaction of sporopollenin with the intestinal mucosa directing to an augmented effectiveness of nutraceutical or drug delivery.Here,current trends and prospects related to the application of plant pollen grains for the delivery of vaccines and drugs and vaccine are discussed.

酮类物质合成酶OsPKS1和Os PKS2对水稻花粉外壁形成的作用

【背景】植物花粉外围包裹的花粉外壁作为植物雄性配子的天然保护屏障对植物的生殖发育起到非常重要的作用。植物花粉外壁的主要成分是孢粉素,主要由脂类物质和酚类物质构成。因此,脂类物质和酚类物质的代谢是植物花药内外壁形成和花粉外壁形成的关键步骤。在其合成过程中,PKS1/PKSA/LAP6和PKS2/PKSB/LAP5在不同物种间发挥保守的生化功能。【目的】通过研究水稻OsPKS1和OsPKS2在花药内外壁和花粉外壁发育过程中的作用,为水稻花药内外壁和花粉外壁合成机理提供新认识。【方法】水稻花药发育基因共表达网络AntherNet预测到一个可能参与孢粉素合成的基因OsPKS1,利用CRISPR/Cas9技术在野生型9522背景和突变体ospks2背景下敲除OsPKS1获得ospks1单突变体和ospks1 ospks2双突变体。在同一生长条件下比较野生型和突变体植株表型,分析突变体植株的营养生长和花器官发育情况。通过I2-KI染色分析ospks1和ospks1 ospks2的花粉活力。通过半薄切片观察野生型和突变体各个时期花药四层细胞发育及小孢子发育,利用扫描电子显微镜观察野生型和突变体花药外壁、花药内壁和花粉外壁表面的精细结构,利用透射电子显微镜观察野生型和突变体花药壁细胞、花粉外壁和乌氏体的精细结构。【结果】获得4个ospks1单突变体和4个ospks1 ospks2双突变体,其中,ospks1-3是纯合的单突变体,ospks1-4 ospks2是纯合的双突变体。ospks1-3和ospks1-4 ospks2均呈现雄性不育的表型。ospks1-3与ospks2的花粉外壁和乌氏体结构均不正常,但两者结构不同。ospks1-3花药表面可形成凸起的外壁结构;绒毡层可正常降解。花粉外壁内部形成大量微小的空洞,柱状体变短,无法有效连接覆盖层和花粉外壁内层;乌氏体的底部结构减小,顶部结构增多,并且较野生型更为尖锐。ospks1-4 ospks2花药外壁角质层减少;绒毡层无法正常降解。小孢子表面无花粉外壁,在11期降解;乌氏体在9期形态异常,数目变少,到11期从绒毡层脱落。【结论】PKS1/PKSA/LAP6和PKS2/PKSB/LAP5的功能在多个物种间均保守,可以影响孢粉素的合成和堆积。但在水稻中两者对于花粉外壁内部结构身碎骨和乌式体形成的功能不同:OsPKS1对柱状层的形成以及乌氏体的底部结构形成更为重要;而OsPKS2对于覆盖层的形成以及乌氏体的顶部结构更为重要。两者互相补充,共同调控花粉外壁、花药外壁的形成和绒毡层的降解。

新型植物基载体对乳糖酶的高效递送及保护

为解决口服酶制剂易被胃液的强酸环境破坏其效价,影响乳糖不耐受症治疗效果的问题,制备一种可以保护乳糖酶过胃而不失去活性的新型植物基载体。采用新型植物基材料向日葵孢粉素外壁胶囊为载体,用于乳糖酶的负载及保护。通过负载、包膜、释放等实验以及采用扫描电子显微镜、激光共聚焦显微镜等表征手段,确定5%海藻酸钠与6%羧甲基茯苓多糖在体积比为1∶1混合所得的凝胶球体外释放效果最佳,实现在消化道中的响应性释放。进一步实验发现,经冻干处理后该体系也具备成为乳糖酶冻干保护剂的潜力。基于此,实验成功论证了向日葵孢粉素外壁胶囊递送体系可以作为乳糖酶的高效递送及保护载体的可行性,为乳糖不耐受症的治疗提供了新的思路。

基于孢粉素微胶囊的共包埋、保护及递送益生菌和乳糖酶的体系

研究旨在开发基于天然植物微胶囊的核壳结构载体,作为益生菌和乳糖酶的递送及保护体系。该核壳结构的孢粉素外壁胶囊(sporopollenin exine capsules,SECs)为核,海藻酸钙(Ca-alginate,Ca-Alg)/羧甲基茯苓多糖(carboxymethylpachymaran,CMP)凝胶为壳,对益生菌的负载量高达9.63×10^(9) CFU/g,乳糖酶活力保留率高达80.72%。在Ca-Alg/CMP壳中,CMP引入可以改变凝胶壳层对水的结合能力,从而改变其溶胀行为和微观结构,借此影响体系中益生菌和乳糖酶的释放行为。结果表明,引入CMP可使Ca-Alg/CMP凝胶包裹的负载益生菌及乳糖酶的SECs在胃肠道中表现出更加优异的稳定性:在模拟消化600 min后,活菌数超过10^(7) CFU/mL,酶活力保留率约为62%。相比于纯菌液和纯酶液,该体系可减少冻干和贮存处理后菌数和酶活力损失率(P<0.05)。最后,利用甲基纤维素对核壳结构进行二次包埋,可提高体系中益生菌和乳糖酶的热稳定性(P<0.05)。

合成固载希夫碱配合物作为配体交换材料(英文)

Two new sporopollenin-immobilized Schiff bases,S-[N-(2-aminoetil) salicylaldiimino] and S-[N-(2-aminoetil) benzaldiimino],and their cobalt(III) and nickel(II) complexes,S-[N-(2-aminoetil) benzaldiimino] aquatriacetato cobalt(III),S-[N-(2-aminoetil) salicylaldiimino] aquadiacetato cobalt(III),S-[N-(2-aminoetil) benzaldiimino] diacetato nickel(II),and S-[N-(2-aminoetil) salicylaldiimino] diacetato nickel(II),were synthesized onto a chemically modified sporopollenin with ethylenediamine.The immobilized ligands and their metal complexes were characterized by thermal analysis and spectroscopic techniques such as infrared,ultraviolet-visible,and atomic absorption spectrometry.Immobilized Schiff base metal complexes,S-[N-(2-aminoetil) benzaldiimino] aquatriacetato cobalt(III) and S-[N-(2-aminoetil) salicylaldiimino] aquadiacetato cobalt(III),were used as ligand exchanger media to investigate ligand adsorption behavior of methylene blue(MB) with column technique.The result shows that the chelation of methylene blue with S-[N-(2-aminoetil) salicylaldiimino] aquadiacetato cobalt(III) complex increases ligand adsorption capacity.

Atomic force microscopic observation on substructure of pollen exine in Cedrus deodara and Metasequoia glyptostroboides

The substructure of pollen exine in Cedrus deodara (Roxb.) Loud, and Metasequoia glyptostroboides Hu et Cheng has been examined with an atomic force microscope (AFM). The results indicate that the exine substructure units containing sporopollenin in two species are similar in shape, which are granular, but slightly different in size. In Cedrus the substructure unit of pollen exine appears to be 56-99 nm long and 42-74 nm wide, while in Metasequoia it appears to be 81-118 nm long and 43-98 nm wide. It has been observed that the subunits of pollen exine in Cedrus arranged tightly to form short-rod-like or spheroidal pollen exine units, several or more than ten of which formed an island-like structure. There are various spaces among these island-like structures which are interconnected to occupy the entire pollen exine. In Metasequoia, the subunits of pollen exine also arranged tightly with a distribution tendency of cluster of 3-10, however, no obvious boundary exists among these clusters. From our

Pollen wall pattern in Arabidopsis

The pollen wall is a solid and variously sculptured structure. This pattern is determined inside a tetrad. During meiosis, the callose wall is formed outside of the meiocyte/microspore to form a tetrad. Then, primexine is deposited between the callose wall and the microspore plasma membrane which will become undulated. The sporopollenin deposits on top of the undulated membrane and develops into the pollen wall pattern, while the callose wall is gradually degraded. In recent years, much progress has been made in the study of pollen wall pattern formation, at both molecular and genetic levels. In this review,we summarize these achievements mainly in Arabidopsis.

NERD1 is required for primexine formation and plasma membrane undulation during microsporogenesis in Arabidopsis thaliana

The primexine formation and plasma membrane undulation are the crucial steps of pollen wall formation in many angiosperms.However,the molecular mechanism underlining these processes is largely unknown.In Arabidopsis,NEW ENHANCER OF ROOT DWARFISM1(NERD1),a transmembrane protein,was reported to play pleiotropic roles in plant development including male fertility control;while,how NERD1 disruption impacts male reproduction is yet unclear.Here,we revealed that the male sterility of nerd1 mutants is attributed to defects in early steps of pollen wall formation.We found that nerd1-2 is void of primexine formation and microspore plasma membrane undulation,defective in callose deposition.Consequently,sporopollenin precursors are unable to deposit and assemble on the microspore surface,but instead accumulated in the anther locule and tapetal cells,and ultimately leading to microspore abortion.NERD1 is localized in the Golgi and is expressed in both vegetative and reproductive organs,with the highest expression in reproductive tissues,including the tapetum,male meiocytes,tetrads and mature pollen grains.Our results suggest that NERD1 is required for the primexine deposition and microspore plasma membrane undulation,thus essential for sporopollenin assembly and pollen exine formation.