Inefficient inorganic phosphate (Pi) fertilizer use exacerbates phosphorus resource depletion and environmental pollution. Purple acid phosphatases (PAPs) are crucial for plant adaptation to a Pi deficiency. In elephant grass (Pennisetum purpureum), 50 PpPAP genes were identified and classified into 13 low-molecular-weight (LMW) and 37 high-molecular-weight members. Transcriptomic analysis and RT-qPCR validation revealed that 17 PpPAPs responded to Pi starvation, notably the tandem-duplicated LMW gene PpPAP17a. This gene, which is uniquely conserved in elephant grass, was strongly upregulated in Pi-deficient roots. Yeast one-hybrid and dual-luciferase assays confirmed that its expression was directly activated by the phosphate starvation response regulators PpPHR20 and PpPHR34. Enzymatic assays showed that PpPAP17a efficiently hydrolyzes ATP and localizes to the plasma membrane and nucleus. Functionally, overexpressing PpPAP17a in rice enhanced acid phosphatase activity, increased phosphorus content, improved root growth and photosynthesis, and ultimately improved grain yield under low-Pi conditions. Thus, PpPAP17a represents a key candidate for developing Pi-efficient crops.

BSA-seq and fine mapping revealed a 294 kb deletion on chromosome 9 regulating leaflet size and biomass in pigeonpea. Leaf size critically influences photosynthetic capacity, impacting organic matter production and biomass yield. This study reports the identification and characterization of a small leaflet mutant (sl1) in pigeonpea (Cajanus cajan) generated via aerial mutagenesis. Compared to the wild-type Qiongzhong, sl1 displayed significantly reduced leaf area, plant height, stem diameter, and biomass, characteristic of a dwarf phenotype. Genetic analysis confirmed a single recessive locus controlling the sl1 phenotype. Bulked segregant analysis sequencing (BSA-seq) and fine mapping identified the causal mutation as a 294 kb deletion encompassing 21 genes on chromosome 9. Transcriptomic analysis identified 1,039 differentially expressed genes (DEGs), indicating disruptions in, among others, plant hormone signaling pathways. Analysis of 28 target plant hormone metabolites revealed significant shifts in sl1 mutant compared to wild-type, including increased levels of strigolactone, methyl indole-3-acetate, and trans-zeatin-riboside, and decreases in gibberellin A3, N6-isopentenyladenine, and methyl jasmonate. Cytological analysis revealed a decreased cell number in sl1 leaves, contributing to the reduced leaflet size. Three candidate genes, CC09g01700, CC09g01705, and CC09g01707, within the deleted region were prioritized based on their altered expression patterns and their putative roles in leaf development. These findings elucidate the genetic regulation of leaf morphology and biomass in pigeonpea, offering potential targets for marker-assisted selection to enhance pigeonpea yield.

Anthracnose, caused by the hemibiotrophic fungus Colletotrichum gloeosporioides, is one of the most destructive diseases affecting leguminous forage crops worldwide. Due to its broad host range and ability to cause severe yield losses, identifying genetic resistance is crucial for sustainable disease management. Stylosanthes guianensis, a diploid, self-pollinating tropical legume widely cultivated as forage, cover crop, and green manure, exhibits natural variation in anthracnose resistance, making it an ideal model for investigating host resistance genes. In this study, we evaluated the resistance of 28 S. guianensis accessions to C. gloeosporioides, revealing a significant positive correlation between phenylalanine ammonia-lyase (PAL) activity and anthracnose resistance. Transcriptome profiling identified five SgPAL genes, with SgPAL1 and SgPAL2 showing particularly strong induction upon pathogen infection and correlation with PAL activity. Functional characterization confirmed these genes encode cytoplasmically localized PAL enzymes. Overexpression of SgPAL1/2 in Arabidopsis thaliana enhanced resistance to C. gloeosporioides, while integrated transcriptomic, metabolomic, and biochemical analyses demonstrated that SgPAL1/2-mediated resistance operates through upregulation of lignin biosynthesis pathways, resulting in increased total lignin content and altered guaiacyl (G)/syringyl (S) monomer ratios. This study identified SgPAL1/2 as crucial genetic regulators of lignin-mediated anthracnose resistance. Our findings further revealed that the increase in both lignin content and the G/S ratio are significant factors enhancing resistance, offering promising targets for the genetic improvement of forage legume crops.

Pigeonpea (Cajanus cajan) is a nutrient-rich and versatile food legume crop of tropical and subtropical regions. In this study, we describe the de novo assembly of a high-quality genome for the ancient pigeonpea landrace 'D30', achieved through a combination of Pacific Biosciences high-fidelity (PacBio HiFi) and high-throughput chromatin conformation capture (Hi-C) sequencing technologies. The assembled 'D30' genome has a size of 813.54 Mb, with a contig N50 of 10.74 Mb, a scaffold N50 of 73.07 Mb, and a GC content of 35.67%. Genomic evaluation revealed that the 'D30' genome contains 99.2% of Benchmarking Universal Single-Copy Orthologs (BUSCO) and achieves a 29.06 long terminal repeat (LTR) assembly index (LAI). Genome annotation indicated that 'D30' encompasses 431.37 Mb of repeat elements (53.02% of the genome) and 37 977 protein-coding genes. Identification of single-nucleotide polymorphisms (SNPs), insertions/deletions (indels), and structural variations between 'D30' and the published genome of pigeonpea cultivar 'Asha' suggests that genes affected by these variations may play important roles in biotic and abiotic stress responses. Further investigation of genomic regions under selection highlights genes enriched in starch and sucrose metabolism, with 42.11% of these genes highly expressed in seeds. Finally, we conducted genome-wide association studies (GWAS) to facilitate the identification of 28 marker-trait associations for six agronomic traits of pigeonpea. Notably, we discovered a calmodulin-like protein (CcCML) that harbors a dominant haplotype associated with the 100-seed weight of pigeonpea. Our study provides a foundational resource for developing genomics-assisted breeding programs in pigeonpea.

Pigeon pea is a perennial leguminous plant that is widely cultivated as a forage and pharmaceutical plant in subtropical and tropical areas, especially in artificial grasslands. Higher seed shattering is one of the most important factors in potentially increasing the seed yield of pigeon pea. Advance technology is necessary to increase the seed yield of pigeon pea. Through 2 consecutive years of field observations, we found that fertile tiller number was the key component of the seed yield of pigeon pea due to the direct effect of fertile tiller number per plant (0.364) on pigeon pea seed yield was the highest. Multiplex morphology, histology, and cytological and hydrolytic enzyme activity analysis showed that shatter-susceptible and shatter-resistant pigeon peas possessed an abscission layer at the same time (10 DAF); however, abscission layer cells dissolved earlier in shattering-susceptible pigeon pea (15 DAF), which led to the tearing of the abscission layer. The number of vascular bundle cells and vascular bundle area were the most significant negative factors (p< 0.01) affecting seed shattering. Cellulase and polygalacturonase were involved in the dehiscence process. In addition, we inferred that larger vascular bundle tissues and cells in the ventral suture of seed pods could effectively resist the dehiscence pressure of the abscission layer. This study provides foundation for further molecular studies to increase the seed yield of pigeon pea.

对41份木豆（Cajanus cajan）种质资源进行种子萌发期抗旱性综合评价，测定发芽特性、活力指数、根系表面积和根系体积等10项指标，通过变异系数分析、相关性分析、主成分分析、隶属函数分析和聚类分析，对其进行萌发期抗旱性综合评价，同时分析干旱胁迫下不同抗旱性木豆的生理响应机理的差异。结果表明：41份木豆种子萌发期抗旱性差异显著，可将41份木豆种质资源划分成高抗旱型（1份）、抗旱型（10份）、中间型（28份）和敏感型（2份）4个类别。相对活力指数、相对根冠比、相对鲜重和相对根系平均直径可作为木豆萌发期抗旱性评价指标。高抗旱型木豆幼苗的SOD、POD和CAT酶活能力优于其他类别。通过综合评价，筛选出11份（D21024、D21035、D21022、D21094、D21031、D21030、D21061、D21134、D21136、D21009、D21023）萌发期抗旱性强的木豆种质，有望在干旱地区进行推广种植。

Stylosanthes spp. (stylo) are annual or perennial legume forages that are widely grown as forage and cover crops in tropical and subtropical regions. However, the seed yield of stylo is very low due to serious seed shattering. In the present study, we found that, although seed shattering was common among the stylo accessions, the shattering rates were genetically different. Therefore, we first synthesized the morphological, histological characteristic, physiochemical, and transcriptome analyses to determine the seed shattering mechanism in stylo. In general, the stylo germplasm with shorter lobules and thicker stems had a lower seed shattering rate and a higher seed weight. The seed and seed stalk joint is the abscission zone in stylo. Multiplex histology and hydrolytic enzyme activity analysis showed that the tearing of the abscission zone occurs due to the intense enzymatic degradation of polygalacturonase and cellulase in the seed shattering-susceptible accession TF0275. cDNA libraries from the abscission zone tissues of TF0041 and TF0275 at 14, 21, and 28 days after flowering were constructed and sequenced. A total of 47,606 unigenes were annotated and 18,606 differentially expressed genes (DEGs) were detected, including 9,140 upregulated and 9,446 downregulated unigenes. Furthermore, the 26 candidate DEGs involved in lignin biosynthesis, cellulase synthesis, and plant hormone signal transduction were found at all three developmental stages. This study provides valuable insights for future mechanistic studies of seed shattering in stylo.

对41份木豆(Cajanus cajan)种质资源进行萌发期耐盐性综合评价,测定发芽率、发芽指数、活力指数、根系表面积和根系体积等10项指标,通过变异系数分析、相关性分析、主成分分析、隶属函数分析和聚类分析,对其进行萌发期耐盐性综合评价.同时,对筛选出的不同耐盐性木豆种质,测定幼苗的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,分析盐胁迫下不同耐盐性木豆的生理响应机理的差异.结果表明:41份木豆种子萌发期耐盐性存在显著差异,筛选出相对根长、相对根冠比、相对发芽指数和相对根系平均直径可作为木豆萌发期耐盐性评价指标.基于隶属函数值进行聚类分析,可将41份木豆种质资源划分成高耐盐型(1份)、耐盐型(10份)、中间型(23份)和盐敏感型(7份)4个类别.不同耐盐性木豆在盐胁迫下的生理响应表明,高耐盐型和耐盐型材料的细胞质膜透性和酶活能力优于盐敏感型.

为探讨木豆[Cajanus cajan(L.)Millsp.]响应低温胁迫的机制,本研究以1份耐低温(MD)和1份低温敏感(QZ)木豆为试验材料,经4℃低温胁迫处理后进行RNA-seq测序分析,结果表明:2份木豆RNA-seq获得了丰富的转录本信息,对转录因子和差异表达基因的基因功能进行注释.木豆响应响应低温胁迫的转录因子主要包括MYB,AP2-EREBP等;在两份材料中,GO分析发现DEGs注释在细胞组成中"膜"和生物学过程中"细胞过程",KEGG分析均显著富集在"核糖体"通路中,而MD中还显著富集在植物激素信号转导、昼夜节律-植物等通路.通过两份材料对比,在MD材料中发现特有与耐低温相关的150个DEGs,主要为α-1,4-葡萄糖苷酶,参与碳水化合物、脂质代谢等途径.还筛选37个与耐寒相关重要差异表达基因和14条通路,并对10个DEGs进行qRT-PCR验证.本文从分子水平阐述了木豆低温胁迫下的响应机制,为未来木豆的抗寒育种奠定了理论基础.

为明确3种圭亚那柱花草(Stylosanthes guianensis Sw.)('热研2号'、'热研5号'和热研21号)的根系分泌物对杂草生长的化感效应,采用营养液培法分别收集其根系分泌物,研究其对5种外来入侵杂草幼苗形态特征及生物量分配的影响.结果表明,除对含羞草(Mimosa pudica L.)幼苗无显著影响外,3种圭亚那柱花草对其余4种杂草的总化感综合效应均为抑制作用.'热研5号'柱花草对杂草幼苗生长的化感抑制效应强于其他二者,对蒺藜草(Cenchrus echinatus L.)幼苗的根长、株高、地下生物量、地上生物量、总生物量和根冠比均有显著抑制效应(P<0.05),对羽芒菊(Tridax procumbens L.)幼苗的侧根数、地下生物量和根冠比有显著抑制效应(P<0.05),也显著抑制假臭草(Eupatorium catarium V.)幼苗的生物量向地下分配(P<0.05),仅对鬼针草(Bidens pilosa L.)幼苗的抑制效应相对较弱.灰色关联分析表明,进行圭亚那柱花草的化感效应研究中应重点关注总生物量、地上生物量和株高.由此推测,3种圭亚那柱花草品种中,'热研5号'柱花草具有防控外来入侵杂草的潜力.

Pigeonpea (Cajanus cajan) is an important legume food crop and plays a crucial role in a secure food supply in many developing countries. Several previous studies have suggested that pigeonpea has great potential for phosphorus (P) deficiency tolerance, but little is known about the underlying mechanism. In this study, the physiological and molecular responses of pigeonpea roots to phosphate (Pi) starvation were investigated through integrating phenotypic, genomic, transcriptomic, metabolomic, and lipidomic analyses. The results showed that low-Pi treatment increased total root length, root surface area, and root acid phosphatase activity, and promoted the secretion of organic acids (e.g. citric acids, piscidic acids, and protocatechuic acids) and the degradation of phospholipids and other P-containing metabolites in the roots of pigeonpea. Consistent with the morphological, physiological, and biochemical changes, a large number of genes involved in these Pi-starvation responses were significantly upregulated in Pi-deficient pigeonpea roots. Among these Pi-starvation response genes upregulated by low-Pi treatment, four gene families were expanded through recent tandem duplication in the pigeonpea genome, namely phosphate transporter 1 (PHT1), phosphoethanolamine/phosphocholine phosphatase (PECP), fasciclin-like arabinogalactan protein (FLA), and glutamate decarboxylase (GAD). These gene families may be associated with Pi uptake from the soil, phospholipid recycling, root morphological remodeling, and regulation of organic acid exudation. Taken together, our results suggest that pigeonpea employs complex Pi-starvation responses to strengthen P acquisition and utilization during low-Pi stress. This study provides new insights into the genome evolution and P deficiency adaptation mechanism of pigeonpea.

本研究采用水培的方法,先用1.0 mmol/L镉对181份海雀稗(Paspalum vaginatum Sw.)胁迫8d,再增加镉浓度到1.5 mmol/L胁迫到第13天,通过测定枯黄率(LF)、坪用质量(TQ)、萎蔫等级(WD)、地上部分镉含量(SDW)、地下部分镉含量(RDW),对181份海雀稗种质进行耐镉性和镉富集能力评价.结果 表明,海雀稗种质间耐镉性和镉富集能力差异显著(P＜0.05),地下部分镉含量高达23256.17 mg/kg,显著高于地上部分(P＜0.05);相关性分析结果表明,相对枯黄率(RLF)、坪用质量指数(TQI)、萎蔫指标间均呈极显著正相关(P＜0.001),相关系数在0.43～0.76之间.对形态指标进行主成分分析,可提取到3个主成分,解释了总变异的92.90％.通过隶属函数法和聚类分析,将181份海雀稗种质分为A、B、C、D、E五类,其中C类耐镉性较好、镉富集能力较强,包括18HN-72、18HN-95、18HN-99、PI647678、PI647886、PI6478956个种质,可作为修复镉污染土壤的备选植物.本研究结果为海雀稗种质资源的分类、选育提供科学依据和线索.

为研究NaCl胁迫对木豆种子发芽及幼苗生长的影响,采用不同质量分数NaCl溶液对5份分别来源于印度(YD1)、缅甸(MD1)、云南(YN1)、广西(GX1)和广东(GD1)的木豆种子和幼苗进行胁迫处理.分别采用培养皿发芽法和水培法,设置不同质量分数的NaCl处理,通过观测木豆种子萌发特性和幼苗生长状况,分析NaCl胁迫对木豆种子萌发和幼苗生长的影响,并通过隶属函数分析对木豆耐盐性进行综合评价,计算木豆NaCl胁迫的临界值.结果表明:在萌发期,NaCl胁迫抑制种子萌发及生长,5份木豆种质资源耐盐能力强弱次序为MD1>GX1>YD1>GD1>YN1.幼苗期,随NaCl质量分数增大,木豆幼苗地上及地下部生长均被显著抑制,5份木豆耐盐能力强弱次序为MD1>GX1>GD1>YD1>YN1.在种子萌发期和幼苗期,5份不同木豆耐盐能力强弱次序并不完全一致,MD1和GX1为耐盐种质,YN1为盐敏感种质.萌发期和幼苗期,5份木豆NaCl胁迫临界值范围分别为0.377％～0.748％和0.275％～0.510％.

种质资源遗传多样性和群体结构分析是作物种质资源保护和作物遗传育种的前提条件.本研究从96对简单序列重复(Simple sequence repeat,SSR)标记中筛选出42对多态性标记,对不同地理来源的72份木豆(Caj anus caj an)种质资源遗传多样性和群体结构进行了分析.结果表明:42对SSR标记在72份不同木豆种质间共检测到等位基因118个,每个标记可检测到2～5个等位基因,平均2.8个;每个SSR标记的Shannon信息指数和多态性信息含量在0.101～1.469和0.040～0.704,平均为0.844和0.442;根据SSR标记数据进行遗传多样性分析,可将72份木豆种质资源分为3类,聚类结果和地理来源并不完全一致;群体结构分析发现79.17％ 的木豆种质资源遗传背景比较单一,20.83％ 的资源拥有复杂的遗传背景.本研究将为木豆种质资源收集和杂交亲本的选择提供重要参考.

海雀稗是重要的暖季型草坪草,为筛选耐镉海雀稗优质资源,本试验在海雀稗耐镉评价体系优化的基础上,对23份海雀稗种质资源进行耐镉性评价,并初步探讨了其耐镉生理机制.结果表明,低浓度镉(0.50～1.50 mmol/L)处理时,海雀稗叶片枯黄率有显著差异,镉浓度为0.50 mmol/L与1.50 mmol/L时坪用质量无显著差异,镉浓度为1.00 mmol/L与1.50 mmol/L时坪用质量无显著差异,坪用质量与枯黄率在镉浓度为1.50～2.00 mmol/L均有显著差异,高浓度镉(2.0～3.0 mmol/L)处理时枯黄率差异显著,镉浓度为2.00 mmol/L与2.50 mmol/L、2.50 mmol/L与3.00 mmol/L时坪用质量间无显著差异.以叶片枯黄率50％为标准,通过建立回归方程求得临界浓度为1.5 mmol/L.选用坪用质量较好的23份海雀稗种质资源进行耐镉性评价,结果表明1.50 mmol/L镉胁迫条件下,不同材料之间耐镉能力差异明显,USA17-2、USA17-30、USA17-37、USA17-41和USA17-45相对坪用质量高,枯黄率低于45.00％,对镉耐性强;USA17-22、USA17-24、USA17-42、HN17-35和US17-47相对坪用质量低,最高枯黄率达到83.33％,对镉耐性最弱.通过对耐镉能力极端资源的脯氨酸及叶绿素含量测定发现,镉胁迫后耐镉海雀稗中脯氨酸和叶绿素含量显著高于镉敏感型海雀稗,推测维持高的脯氨酸和叶绿素含量是海雀稗耐镉的重要生理机制.本研究结果为选育优良耐镉海雀稗品种提供参考.

木豆是世界第六大食用豆类,用途非常广泛.木豆遗传多样性非常丰富,植物种质资源特性与其抗逆性密切相关.本综述重点介绍国内外木豆种质资源遗传多样性、抗逆生理生化指标及机制研究进展,同时对木豆产业化研究提出展望,为后期开展木豆抗逆研究及抗逆育种提供参考依据.

Seashore paspalum (Paspalum vaginatum) is an important warm-season turfgrass distributed in tropical and coastal areas. It has excellent resistance to abiotic stresses, such as salinity, drought, and low temperature. However, the research on genetic diversity of local P. vaginatum collections from China is limited. In this study, the genetic diversity among 58 P. vaginatum accessions from four different provinces in China and four cultivars were assessed using simple sequence repeat (SSR) markers. The results indicated that a total of 45 alleles were detected by 19 polymorphic markers, with a range of 2 to 4 and an average of 2.4 alleles per marker. The genetic similarity coefficients between each pair of the 58 P. vaginatum accessions and four cultivars ranged from 0.51 to 1.00, with an average of 0.77. The range of variation of Shannon diversity index of each SSR marker was 0.047 to 1.075, with an average of 0.486. The polymorphic information content of each SSR marker varies from 0.016 to 0.577, with an average of 0.249. The results of cluster analysis and principal component analysis (PCA) showed that 58 P. vaginatum accessions and four cultivars were divided into four groups. These results provide the theoretical basis for the genetic diversity assessments and molecular marker–assisted breeding of P. vaginatum species.

对2个耐荫性具有显著（P＜0.05）差异的普通钝叶草（Stenotaphrumhelferi）品系S17（耐荫强）与S34（耐荫弱）设置3个不同程度（自然光照、70%自然光照、25%自然光照）遮光处理,对其形态及生理生化差异进行分析。结果表明,经遮荫处理后耐荫性强的S17相对叶长、相对叶宽、相对绿色覆盖度、相对草坪密度、相对坪用质量、相对地上干物重及相对光合色素含量均显著（P＜0.05）高于耐荫性弱的S34,且重度胁迫显著（P＜0.05）高于轻度胁迫;遮荫后S17的相对叶绿素a/b逐渐增加,而S34逐渐降低;重度遮荫后,相对可溶性糖及相对可溶性蛋白含量显著（P＜0.05）低于轻度胁迫,其中S17显著（P＜0.05）高于S34。本研究对今后开展普通钝叶草耐荫新品种选育和QTL定位提供参考。

木豆(Cajanus cajan)是一种药食兼用型的豆科植物,为了对木豆不同种质资源植物形态特征、活性成分和代谢产物进行质量分析,本研究以叶片含水量、浸出物、总黄酮、多糖与外部形态特征为指标对10份木豆种质的质量进行差异比较,进而对4份差异种质(3-QZ、4-HK、5-DH3和6-DZ)进行代谢差异分析.结果表明:不同种质在形态性状上具有丰富的遗传变异,变异系数范围在8.75％(百粒重)～37.96％(分枝);水分含量与叶长、浸出物与荚果长、叶型指数与花序轴长度、花序轴长度与旗瓣大小和荚果宽以及荚果长与荚果宽和百粒重之间均呈显著相关关系(P<0.05);总黄酮含量与旗瓣大小、叶长与叶宽、叶型指数与荚果宽、荚果宽与百粒重均呈极显著相关关系(P<0.01);不同品系间活性成分存在显著差异(P<0.05);根据外形形态和活性成分分析,选取4份种质进行代谢物质差异分析,共获得脂类、有机酸、萜类、生物碱、鞣质、氨基酸及其衍生物、酚酸类、核苷酸及其衍生物、黄酮、醌类、木脂素和香豆素及其他类化合物453个,其中黄酮类化学物最多,不同品系间化合物物质含量差异显著(P<0.05).本研究结果可为今后开展木豆新品种选育和药效成分分析提供参考.