Explore the vast range of titles available.

This investigation focuses on the structural, semantic and aspectual properties of passive in Mandarin Chinese (MC) and European Portuguese (EP) from a descriptive perspective. The findings reveal systematic divergences between the two systems. MC passives can be overtly marked by bei or remain unmarked, relying on the semantic tendency and semantic role between patient and agent. While agent omission alone preserves the bei-passive construction, the simultaneous deletion of both the agent and the bei marker yields an unmarked passive with fundamentally different structural and semantic properties. In contrast, EP agent omission merely alternates between long and short forms of a unified structure. Aspectually, MC passives exhibit covert properties requiring inferential interpretation, demonstrating flexibility in combining with aspectual particles—a pattern absent in EP's morphologically-marked system. This contrast reflects a deeper asymmetry: MC passives are primarily lexically governed, while EP passives rely predominantly on morphological inflection. These divergent realization mechanisms can be traced to underlying typological differences—MC's topic-prominence and morphological minimality versus EP's subject-prominence and rich inflectional morphology. By examining how these typological properties specifically constrain passive constructions, this study contributes to understanding the interaction between morphological systems, lexical mechanisms, and passive realization across typologically distinct languages. A presente investigação centra-se nas propriedades estruturais, semânticas e aspectuais da passiva em Chinês Mandarim (CM) e Português Europeu (PE), revelando divergências sistemáticas entre os dois sistemas linguísticos. As passivas do CM podem ser marcadas por bei ou permanecer não marcadas, dependendo da tendência semântica e do papel semântico entre paciente e agente. Enquanto a omissão do agente preserva a construção passiva com bei, a eliminação simultânea do agente e de bei resulta numa passiva não marcada com propriedades distintas. A omissão do agente em PE alterna apenas entre formas longas e curtas de uma estrutura unificada. Aspectualmente, as passivas do CM exibem propriedades implícitas que requerem interpretação inferencial, demonstrando flexibilidade na combinação com partículas aspectuais: padrão ausente no PE. Este contraste reflete uma assimetria profunda: as passivas do CM são governadas a nível lexical, enquanto as do PE dependem da flexão morfológica. Estas divergências atribuem-se a diferenças tipológicas: a proeminência de tópico e minimalidade morfológica do CM versus a proeminência de sujeito e morfologia flexional rica do PE. Ao examinar como estas propriedades tipológicas restringem as construções passivas, o estudo contribui para compreender a interação entre sistemas morfológicos, mecanismos lexicais e realização da passiva em línguas tipologicamente distintas.  

Drought and high temperatures are two major abiotic stress factors that often occur simultaneously in nature, affecting negatively crop performance and yield. Moreover, these environmental challenges induce oxidative stress in plants through the production of reactive oxygen species (ROS). Carrizo citrange and Cleopatra mandarin are two citrus genotypes with contrasting ability to cope with the combination of drought and heat stress. In this work, a direct relationship between an increased antioxidant activity and stress tolerance is reported. According to our results, the ability of Carrizo plants to efficiently coordinate superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and glutathione reductase (GR) activities involved in ROS detoxification along with the maintenance of a favorable GSH/GSSG ratio could be related to their relative tolerance to this stress combination. On the other hand, the increment of SOD activity and the inefficient GR activation along with the lack of CAT and APX activities in Cleopatra plants in response to the combination of drought and heat stress, could contribute to an increased oxidative stress and the higher sensibility of this citrus genotype to this stress combination.

cv. 'Chunhongtangju' was mutated from Mandarin 'Shatangju', which has been identified as a new citrus variety. Mandarin 'Chunhongtangju' fruits were late-ripening for about two months than Mandarin 'Shatangju'. To understand the pericarp differential development mechanism in Mandarin 'Shatangju' (CK) and 'Chunhongtangju' (LM), hormones and transcriptome profiles of pericarps were performed in different development stages: Young fruit stage (CK1/LM1), Expansion and Turning color stage (CK2), Expansion stage (LM2), Turning color stage (LM3), and Maturity stage (CK3/LM4). In this study, the development of LM was significantly slower, and the maturity was significantly delayed. At the same stage, most hormones in Mandarin 'Chunhongtangju' pericarps were higher than that in 'Shatangju' such as gibberellin A24, cis(+)-12-oxophytodienoic acid, and L-phenylalanine. The deficiency of hormones in late-maturing pericarps was mainly manifested in ABA, 12-OHJA, MeSAG, and ABA-GE. Differences in transcriptome profiles between the two citrus varieties are primarily observed in energy metabolism, signal transduction such as MAPK signaling pathway and plant hormone signaling, and biosynthesis of secondary metabolites. After analyzing the hormones and transcriptome data, we found that the top genes and hormones, such as Cs_ont_5g020040 (transcription elongation factor, ), Cs_ont_7g021670 (BAG family molecular chaperone regulator 5, ), Cs_ont_2g025760 (40S ribosomal protein S27, ), 5-deoxystrigol, salicylic acid 2-O-β-glucosid, and gibberellin A24, contributed significantly to gene transcription and hormone synthesis. This study suggests that the variances of pericarp development between the two varieties are linked to variations in the transcription levels of genes associated with energy and secondary metabolism, signal transduction related genes. These findings expand our understanding of the complex transcriptional and hormonal regulatory hierarchy during pericarp development.

Drought and heat stresses are two of the most frequent environmental factors that take place simultaneously in the field constraining global crop productivity. Metabolism reconfiguration is often behind the adaptation of plants to adverse environmental conditions. Carrizo citrange and Cleopatra mandarin, two citrus genotypes with contrasting ability to tolerate combined heat and drought conditions, showed different metabolite patterns. Increased levels of phenylpropanoid metabolites were observed in Cleopatra in response to stress, including scopolin, a metabolite involved in defense mechanisms. Tolerant Carrizo accumulated sinapic acid and sinapoyl aldehyde, direct precursors of lignins. Finally, Cleopatra showed an accumulation of flavonols and glycosylated and polymethoxylated flavones such as tangeritin. The activation of flavonoid biosynthesis in Cleopatra could be aimed to mitigate the higher oxidative damage observed in this genotype. In general, limonoids were more severely altered in Cleopatra than in Carrizo in response to stress imposition. To conclude, all metabolite changes observed in Cleopatra suggest the activation of energy metabolism along with metabolic pathways leading to the accumulation of photoprotective and antioxidant secondary metabolites, oriented to mitigate the damaging effects of stress. Conversely, the higher ability of Carrizo to retain a high photosynthetic activity and to cope with oxidative stress allowed the maintenance of the metabolic activity and prevented the accumulation of antioxidant metabolites.

The essential oil fraction obtained from the rind of spp. is rich in chemical compounds of interest for the food and perfume industries, and therefore has been extensively studied during the last decades. In this manuscript, we provide a comprehensive review of the volatile composition of this oil fraction and rind extracts for the 10 most studied species: (sweet orange), (mandarin), (grapefruit), (pummelo), (lemon), (citron), (lime), (bitter orange), (bergamot orange), and (yuzu). Forty-nine volatile organic compounds have been reported in all 10 species, most of them terpenoid (90%), although about half of the volatile compounds identified in peel are non-terpenoid. Over 400 volatiles of different chemical nature have been exclusively described in only one of these species and some of them could be useful as species biomarkers. A hierarchical cluster analysis based on volatile composition arranges these species in three clusters which essentially mirrors those obtained with genetic information. The first cluster is comprised by and , and is mainly characterized by the presence of a larger abundance of non-terpenoid ester and aldehyde compounds than in the other species reviewed. The second cluster is comprised by , , , and , and is characterized by the prevalence of mono- and sesquiterpene hydrocarbons. Finally, shows a particular volatile profile with some sulfur monoterpenoids and non-terpenoid esters and aldehydes as part of its main differential peculiarities. A systematic description of the rind volatile composition in each of the species is provided together with a general comparison with those in leaves and blossoms. Additionally, the most widely used techniques for the extraction and analysis of volatile compounds are also described.

Citrus leaves, which are a rich source of plant volatiles, have the beneficial attributes of rapid growth, large biomass, and availability throughout the year. Establishing the leaf volatile profiles of different citrus genotypes would make a valuable contribution to citrus species identification and chemotaxonomic studies. In this study, we developed an efficient and convenient static headspace (HS) sampling technique combined with gas chromatography-mass spectrometry (GC-MS) analysis and optimized the extraction conditions (a 15-min incubation at 100 ˚C without the addition of salt). Using a large set of 42 citrus cultivars, we validated the applicability of the optimized HS-GC-MS system in determining leaf volatile profiles. A total of 83 volatile metabolites, including monoterpene hydrocarbons, alcohols, sesquiterpene hydrocarbons, aldehydes, monoterpenoids, esters, and ketones were identified and quantified. Multivariate statistical analysis and hierarchical clustering revealed that mandarin ( Citrus reticulata Blanco) and orange ( Citrus sinensis L. Osbeck) groups exhibited notably differential volatile profiles, and that the mandarin group cultivars were characterized by the complex volatile profiles, thereby indicating the complex nature and diversity of these mandarin cultivars. We also identified those volatile compounds deemed to be the most useful in discriminating amongst citrus cultivars. This method developed in this study provides a rapid, simple, and reliable approach for the extraction and identification of citrus leaf volatile organic compound, and based on this methodology, we propose a leaf volatile profile-based classification model for citrus.

This work was supported by Ministerio de Economía y Competitividad (MINECO) and Universitat Jaume I through grants No. AGL2013-42038-R and P1IB2013-23, respectively. SIZ was supported by a predoctoral grant from Universitat Jaume I.

Mandarins are the second most farmed citrus. Consumers demand a mandarin fruit that is both tasty and excellent in quality. The fruit quality, flavonoid profile, antioxidant capacity and total carotenoid content of five varieties (‘Zorica’, ‘Chahara’, ‘Kawano Wase’, ‘Owari’ and ‘Saigon’) of Satsuma mandarins grown in Neretva valley (Croatia) were determined. In this research, the distribution of bioactive compounds was different for mandarin juice, dry pulp residue and dry peels. Dry peels showed higher levels of polyphenolic compounds and antioxidant activity. Total carotenoids were found to be in a greater concentration in dry pulp residue than in the dry peel. The highest levels of total carotenoids (543 μg β-carotene/g) were found in the dry pulp residue of ‘Owari’ and ‘Saigon’, while the lowest levels were in ‘Chahara’ (227.87 μg β-carotene/g). In dry mandarin peels, the highest levels of total carotenoids were in ‘Kawano Wase’ (227.58 μg β-carotene/g), and the lowest levels were in ‘Chahara’ (52.24 μg β-carotene/g). The most abundant component of polymethoxyflavones (PMFs) in mandarin dry peel was nobiletin, ranging from 0.204 mg/g (‘Chahara’) to 0.608 mg/g (‘Saigon’), followed by tangeretin, ranging from 0.133 mg/g (‘Chahara’) to 0.251 mg/g (‘Saigon’), and sinesestin (‘Zorica’), ranging from 0.091 mg/g to 0.353 mg/g (‘Saigon’).

The genus Citrus , comprising some of the most widely cultivated fruit crops worldwide, includes an uncertain number of species. Here we describe ten natural citrus species, using genomic, phylogenetic and biogeographic analyses of 60 accessions representing diverse citrus germ plasms, and propose that citrus diversified during the late Miocene epoch through a rapid southeast Asian radiation that correlates with a marked weakening of the monsoons. A second radiation enabled by migration across the Wallace line gave rise to the Australian limes in the early Pliocene epoch. Further identification and analyses of hybrids and admixed genomes provides insights into the genealogy of major commercial cultivars of citrus. Among mandarins and sweet orange, we find an extensive network of relatedness that illuminates the domestication of these groups. Widespread pummelo admixture among these mandarins and its correlation with fruit size and acidity suggests a plausible role of pummelo introgression in the selection of palatable mandarins. This work provides a new evolutionary framework for the genus Citrus . The origin, evolution and domestication of Citrus and the genealogy of the most important wild and cultivated citrus varieties. When life gave us lemons Citrus fruits are one of the most cultivated crops worldwide, yet the evolutionary relationships among citrus species remain uncertain. Daniel Rokhsar, Manuel Talon and colleagues analyse the genomes of 60 accessions that represent a diverse range of citrus species, including 30 newly sequenced citrus genomes. They characterize the diversity and evolution of citrus at the species level and identify interspecific citrus hybrids and admixtures—genetic mixing between previously isolated populations—that could be the result of human activities such as migration and agriculture. The authors identify 10 progenitor species and suggest that citrus originated in southeast Asia, diversifying during the late Miocene epoch through a rapid southeast Asian radiation that correlated with a changing climate, including the weakening of the monsoons. They also find extensive relatedness among mandarins and sweet oranges, showing a complex history of admixture during the domestication of these groups.