Single Plant Species Research Articles

Many bee species, including rare species, are important for function of entire plant-pollinator networks.

It is important to understand how biodiversity, including that of rare species, affects ecosystem function. Here, we consider this question with regard to pollination. Studies of pollination function have typically focused on pollination of single plant species, or average pollination across plants, and typically find that pollination depends on a few common species. Here, we used data from 11 plant-bee visitation networks in New Jersey, USA, to ask whether the number of functionally important bee species changes as we consider function separately for each plant species in increasingly diverse plant communities. Using rarefaction analysis, we found the number of important bee species increased with the number of plant species. Overall, 2.5 to 7.6 times more bee species were important at the community scale, relative to the average plant species in the same community. This effect did not asymptote in any of our datasets, suggesting that even greater bee biodiversity is needed in real-world systems. Lastly, on average across plant communities, 25% of bee species that were important at the community scale were also numerically rare within their network, making this study one of the strongest empirical demonstrations to date of the functional importance of rare species.

Assessing the Impact of Road and Land Use on Species Diversity of Trees, Shrubs, Herbs and Grasses in the Mountain Landscape in Southern Africa

Mountain landscape, described as a global biodiversity hotspot due to high endemism, is threatened by land-use change, including management and modification of vegetation. However, there is little knowledge about how road and land use affect plant diversity in mountains landscapes, particularly in southern Africa. Previous studies have studied the impact of the road or land use on plant species diversity separately and have concentrated on a single plant species. Here we compare the plant diversity of regenerated trees, shrubs, herbaceous plant, and grasses among Forest, Fallow, Agriculture, and Road in the Moribane Forest Reserve (MFR), in Eastern Chimanimani Mountain landscape in Mozambique. To assess how land-use change affects plant diversity, we conducted 45 transects along the roadside and randomly established 24 quadrats in the Agriculture fields and Fallow and 26 quadrats in the pristine Forest. In each transect and quadrats, we recorded the occurrence of four plant life forms (regenerated trees, shrubs, herbaceous, and grass species) to determine the alpha and beta-diversity across land-uses, and we assessed the invasiveness of each species. Species composition varied significantly among the land-uses types. Roadside had higher species diversity and the highest number of invasive species (138 total species of all plant life forms; 31 invasive species), following Agriculture (72; 30), Fallow (81; 20), and Forest (78; 19). There was no similarity in species between roadsides and other land-uses. Furthermore, roadside recorded the highest average species turnover for all plant life forms following Agriculture, Forest, and Fallow. Among the plants, the most important life form was herbaceous with 143 species, following grass with 86 species, shrubs with 86, and regenerated trees with 65 species. The land-use pattern makes the landscape more diversified in the study area and, as a result, increase the plant species richness and diversity by species replacement. This study is unique in collecting and analyzing data on different plant life forms on roadsides linked with a range of different land-use types within a small region of a mountain landscape in southern Africa.

Genotyping-by-sequencing-based identification of Arabidopsis pattern recognition receptor RLP32 recognizing proteobacterial translation initiation factor IF1

Activation of plant pattern-triggered immunity (PTI) relies on the recognition of microbe-derived structures, termed patterns, through plant-encoded surface-resident pattern recognition receptors (PRRs). We show that proteobacterial translation initiation factor 1 (IF1) triggers PTI in Arabidopsis thaliana and related Brassicaceae species. Unlike for most other immunogenic patterns, IF1 elicitor activity cannot be assigned to a small peptide epitope, suggesting that tertiary fold features are required for IF1 receptor activation. We have deployed natural variation in IF1 sensitivity to identify Arabidopsis leucine-rich repeat (LRR) receptor-like protein 32 (RLP32) as IF1 receptor using a restriction site-associated DNA sequencing approach. RLP32 confers IF1 sensitivity to rlp32 mutants, IF1-insensitive Arabidopsis accessions and IF1-insensitive Nicotiana benthamiana, binds IF1 specifically and forms complexes with LRR receptor kinases SOBIR1 and BAK1 to mediate signaling. Similar to other PRRs, RLP32 confers resistance to Pseudomonas syringae, highlighting an unexpectedly complex array of bacterial pattern sensors within a single plant species.

Conserved and Diverse Transcriptional Reprogramming Triggered by the Establishment of Symbioses in Tomato Roots Forming Arum-Type and Paris-Type Arbuscular Mycorrhizae.

Arbuscular mycorrhizal (AM) fungi allocate mineral nutrients to their host plants, and the hosts supply carbohydrates and lipids to the fungal symbionts in return. The morphotypes of intraradical hyphae are primarily determined on the plant side into Arum- and Paris-type AMs. As an exception, Solanum lycopersicum (tomato) forms both types of AMs depending on the fungal species. Previously, we have shown the existence of diverse regulatory mechanisms in Arum- and Paris-type AM symbioses in response to gibberellin (GA) among different host species. However, due to the design of the study, it remained possible that the use of different plant species influenced the results. Here, we used tomato plants to compare the transcriptional responses during Arum- and Paris-type AM symbioses in a single plant species. The tomato plants inoculated with Rhizophagus irregularis or Gigaspora margarita exhibited Arum- and Paris-type AMs, respectively, and demonstrated similar colonization rates and shoot biomass. Comparative transcriptomics showed shared expression patterns of AM-related genes in tomato roots upon each fungal infection. On the contrary, the defense response and GA biosynthetic process was transcriptionally upregulated during Paris-type AM symbiosis. Thus, both shared and different transcriptional reprogramming function in establishing Arum- and Paris-type AM symbioses in tomato plants.

Genetic diversity of the predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) with an overview of its distribution and implications for biological control

Amblyseius swirskii is a predatory mite of the family Phytoseiidae that is widely used in biological control of small insect and mite pests. A population from Israel was the source of material now commercially marketed by several biocontrol companies. The present study aimed to characterize the genetic variability of A. swirskii using 12S rRNA, CytB and COI mtDNA sequences, and explore its geographical distribution based on a compilation of known and newly- reported occurrences, including populations from several countries where this species naturally occurs. Amblyseius swirskii is reported from 22 countries, primarily in the eastern Mediterranean basin and Africa. The species has been reported on 48 plant families, with the highest number of observations on Rosaceae, Rutaceae and Solanaceae, mostly on crops, but also on uncultivated plants. The genetic diversity of A. swirskii was very low in all populations except the one from Cape Verde; all other studied populations were not differentiated from the commercial ones. The results suggest that commercialized and natural populations now co-occur widely, even in natural environments. The Cape Verde population seems to be a distinct natural population with relatively high intra-population variation, even among specimens collected in a single locality and on a single plant species. Further analyses would be required to determine how much the observed genetic differentiation results in different biological features, but the diversity present in the natural Cape Verde populations of A. swirskii may provide a source of novel traits with potential to improve the performance of this natural enemy.

DNA Barcoding Reveals Generalization and Host Overlap in Hummingbird Flower Mites: Implications for the Mating Rendezvous Hypothesis.

AbstractHummingbird flower mites are assumed to monopolize single host plant species owing to sexual selection for unique mating rendezvous sites. We tested the main assumption of the mating rendezvous hypothesis-extreme host specialization-by reconstructing interactions among tropical hummingbird flower mites and their host plants using DNA barcoding and taxonomic identifications. We collected 10,654 mites from 489 flowers. We extracted DNA from 1,928 mite specimens and amplified the cytochrome c oxidase I (CO1) DNA barcode. We analyzed the network structure to assess the degree of generalization or specialization of mites to their host plants. We recorded 18 species of hummingbird flower mites from three genera (Proctolaelaps, Rhinoseius, and Tropicoseius) interacting with 14 species of plants. We found that generalist mites are common, and congeneric mite species often share host plants. Our results challenge the assumption of strict specialization that supports this system as an example of mating rendezvous evolution.

Nutritional and Physiological Regulation of Glassy-Winged Sharpshooter Oogenesis.

The glassy-winged sharpshooter (Homalodisca vitripennis (Germar); Hemiptera: Cicadellidae: Cicadellinae) is an invasive insect that transmits the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadacae). While adult glassy-winged sharpshooter must feed to produce eggs, the role of nutritional status on initiating oogenesis is poorly understood. To determine the effects of glassy-winged sharpshooter nutrition on nymphal development, oogenesis, and fecundity, glassy-winged sharpshooter were reared on cowpea, sunflower, sorghum, and a mixture of the three plant species. Adults emerging from cowpea, sunflower, or plant mixture treatments had shorter development times, attained larger size, and had greater estimated lipid reserves than females reared on sorghum. In choice tests, nymphs avoided sorghum and preferentially fed on cowpea and sunflower. Adult females provisioned with a single plant species during the nymphal stage were provided with either the same host plant species or a mixture of host plant species (cowpea, sunflower, sorghum) for a 9-wk oviposition period, with 37% of females initiating oogenesis. Ovipositing females had greater juvenile hormone and octopamine levels than reproductively inactive females, although topical application of the juvenile hormone analog Methoprene did not promote oogenesis. Across nymphal diets, reproductively active females produced more eggs when held on plant mixtures than on single plant species. In choice tests, adult females were observed most frequently on cowpea, although most eggs were deposited on sorghum, the host least preferred by nymphs. Results suggest that fecundity is largely determined by the quality of the adult diet, although the stimulus that initiates oogenesis does not appear to be related to nutrition.

Updating species diversity of Colletotrichum, with a phylogenomic overview.

The genus Colletotrichum includes important plant pathogens, endophytes, saprobes and human pathogens. Even though the polyphasic approach has facilitated Colletotrichum species identification, knowledge of the overall species diversity and host distribution is largely incomplete. To address this, we examined 952 Colletotrichum strains isolated from plants representing 322 species from 248 genera, or air and soil samples, from 87 locations in China, as well as 56 strains from Saudi Arabia, Thailand, Turkey, and the UK. Based on morphological characteristics and multi-locus phylogenetic analyses, the strains were assigned to 107 species, including 30 new species described in this paper and 18 new records for China. The currently most comprehensive backbone tree of Colletotrichum, comprising 16 species complexes (including a newly introduced C. bambusicola species complex) and 15 singleton species, is provided. Based on these analyses, 280 species with available molecular data are accepted in this genus, of which 139 have been reported in China, accounting for 49.6 % of the species. Colletotrichum siamense, C. karsti, C. fructicola, C. truncatum, C. fioriniae, and C. gloeosporioides were the most commonly detected species in China, as well as the species with the broadest host range. By contrast, 76 species were currently found to be associated with a single plant species or genus in China. To date, 33 Colletotrichum species have been exclusively reported as endophytes. Furthermore, we generated and assembled whole-genome sequences of the 30 new and a further 18 known species. The most comprehensive genome tree comprising 94 Colletotrichum species based on 1 893 single-copy orthologous genes was hence generated, with all nodes, except four, supported by 100 % bootstrap values. Collectively, this study represents the most comprehensive investigation of Colletotrichum diversity and host occurrence to date, and greatly enhances our understanding of the diversity and phylogenetic relationships in this genus. Taxonomic novelties: New species: Colletotrichum arecacearum F. Liu, Z.Y. Ma & L. Cai, Colletotrichum bicoloratum F. Liu, W.P. Wu & L. Cai, Colletotrichum bromeliacearum F. Liu & L. Cai, Colletotrichum buxi F. Liu, W.P. Wu & L. Cai, Colletotrichum chamaedoreae F. Liu, W.P. Wu & L. Cai, Colletotrichum crousii F. Liu, Z.Y. Ma & L. Cai, Colletotrichum danxiashanense F. Liu, W.P. Wu & L. Cai, Colletotrichum diversisporum F. Liu, W.P. Wu & L. Cai, Colletotrichum diversum F. Liu & L. Cai, Colletotrichum dolichoconidiophori F. Liu, W.P. Wu & L. Cai, Colletotrichum iris F. Liu & L. Cai, Colletotrichum monsterae F. Liu, W.P. Wu & L. Cai, Colletotrichum multiseptatum F. Liu, W.P. Wu & L. Cai, Colletotrichum nageiae F. Liu, W.P. Wu & L. Cai, Colletotrichum obovoides F. Liu & L. Cai, Colletotrichum parabambusicola F. Liu, W.P. Wu & L. Cai, Colletotrichum paraendophytum F. Liu, W.P. Wu & L. Cai, Colletotrichum reniforme F. Liu, Z.Y. Ma & L. Cai, Colletotrichum schimae F. Liu, W.P. Wu & L. Cai, Colletotrichum shivasii F. Liu & L. Cai, Colletotrichum sinuatum F. Liu, W.P. Wu & L. Cai, Colletotrichum subacidae F. Liu, Z.Y. Ma & L. Cai, Colletotrichum subsalicis F. Liu & L. Cai, Colletotrichum subvariabile F. Liu, W.P. Wu & L. Cai, Colletotrichum syngoniicola F. Liu, Z.Y. Ma & L. Cai, Colletotrichum telosmae F. Liu, W.P. Wu & L. Cai, Colletotrichum tibetense F. Liu & L. Cai, Colletotrichum variabile F. Liu, W.P. Wu & L. Cai, Colletotrichum zhaoqingense F. Liu & L. Cai, Colletotrichum zhejiangense F. Liu, W.P. Wu & L. Cai. Citation: Liu F, Ma ZY, Hou LW, Diao YZ, Wu WP, Damm U, Song S, Cai L (2022). Updating species diversity of Colletotrichum, with a phylogenomic overview. Studies in Mycology 101: 1-56. doi: 10.3114/sim.2022.101.01.

Conservation biological control of insect pests

Abstract Conservation biological control increases the control effect of locally occurring natural enemies and has two approaches. Ecological engineering of the agroecosystem involves improving the environment in favour of natural enemies. The second approach is to devise ways of improving the ratio of natural enemies to pests by applying an insecticide in a partially selective manner. The tools of ecological engineering are to provide pollen and nectar sources as an adult food for beneficial insects, to increase floral diversity to increase the numbers of other insects that provide alternative food for beneficials, perhaps to add a single plant species to support an essential alternate host for a predator or parasitoid, or to use plant diversity to raise humidity in the crop. These tools have long been available, but have only been exploited more recently as the public and governments have required greater environmental sustainability and pests have increasingly become tolerant to the available insecticides. Few insecticides offer intrinsic selectivity in favour of natural enemies, but selectivity of broad-spectrum compounds can be obtained by reducing the dose of the insecticide or by restricting its application in time or space. Whatever approach is considered, its practical application is usually quite simple.

What can we learn from past and recent Bavarian knowledge for the future development of European veterinary herbal medicine? An ethnoveterinary study

Ethnopharmacological relevanceWhile the interest in finding medical solutions for the worldwide antibiotics crisis is rising, the legal possibility of simplified authorization of herbal veterinary medicinal products is dwindling.An important basis for both the preservation and development of knowledge in veterinary herbal medicine are pharmacological and clinical studies on the performance of herbal remedies, based on historical written sources on the treatment of farm animals with medicinal plants, as well as current ethnoveterinary research.Nevertheless, there is only limited systematic ethnoveterinary research in Europe, with the exceptions of the Mediterranean region, Switzerland and Austria. We conducted a survey on the ethnoveterinary knowledge of farmers in Bavaria, and analyzed two regional historical textbooks. Aim of the studyWe documented the local veterinary knowledge about livestock in Bavaria based upon local historical textbooks and upon ethnoveterinary interviews to discover opportunities for the future development of European veterinary herbal medicine. Material and methodsIn 2018/2019 we conducted 77 semi-structured interviews with 101 farmers from different types of farms. Detailed information about homemade herbal remedies (plant species, plant part, manufacturing process, source of knowledge) and the corresponding use reports (target animal species, category of use, route of administration, dosage, source of knowledge, frequency of use, last time of use and farmers’ satisfaction) were collected. To compare our data with the literature, the use reports of two local historical textbooks were analyzed and compared with the data from the interviews. Results716 homemade remedy reports (HRs) for altogether 884 use reports (URs) were documented in this study. We picked the 363 HRs that consisted of a single plant species with or without other natural products (HSHRs) for a deeper analysis. These HSHRs were prepared from 108 plant species that belonged to 57 botanical families.The most URs were documented for the families of: Asteraceae, Linaceae and Urticaceae. Calendula officinalis L. (Asteraceae), Linum usitatissimum L. (Linaceae) and Urtica dioica L. (Urticaceae) were the most often documented single species. A total of 448 URs were gathered for the 363 HSHRs. The largest number of URs was for treatments of gastrointestinal disorders and metabolic dysfunctions, followed by skin alterations and sores.For nearly half of the URs the source of knowledge was family and friends. For 80 URs the source of knowledge was different from that of the corresponding HSHRs. For 68% of the URs farmers mentioned at least one use during the last 5 years. Half of the plant species that were mentioned in the historical literature were also mentioned in URs by the interviewees. ConclusionIn Bavaria, medicinal plants are actively used by farmers to treat their livestock with a high level of satisfaction. The knowledge is not passed on from generation to generation in a purely static way, but is dynamically developed by the users in almost one fifth of the URs. Ethnoveterinary research combined with data from regional historical textbooks may facilitate pharmacological and clinical studies in veterinary medicine, and the discussion about a simplified registration for traditional herbal veterinary medicinal products.

Actinobacterial biofertilizer improves the yields of different plants and alters the assembly processes of rhizosphere microbial communities

Biofertilizers are not always applicable for the local environment or specific plant species. Therefore, it is necessary to assess the universal effects of a biofertilizer when applied to different plants across regions. Particularly, how actinobacteria-based biofertilizers affect the assembly of rhizosphere microbial communities remains unknown. Here, we assessed the universal validity and regulatory role of a biofertilizer containing Streptomyces pactum Act12 and Streptomyces rochei D74 in reshaping the rhizosphere microbial communities associated with different plants grown in Shaanxi, Inner Mongolia, and Xinjiang of northwest China. A greenhouse pot experiment was conducted with cucumber, and field experiments were conducted with tomato, pepper, sunflower, and jujube. Compared with the control, biofertilizer application improved the yield of the different plants by 7.7%–55.6%. The community composition of rhizosphere fungi shifted in biofertilizer-treated soils, despite no significant differences in the species diversity or richness of bacteria and fungi. For single plant species, the alpha diversity indices of rhizosphere microbial communities showed distinctly different trends in response to biofertilizer application. Following biofertilizer application, the relative abundance of some plant beneficial taxa (such as Chitinophaga, Dokdonella, Pseudoxanthomonas, and Coprinellus) increased, while the relative abundance of some phytopathogenic taxa (such as Cladosporium and Gibberella) decreased. Stochastic processes contributed predominantly to the bacterial community assembly, whereas the relative contribution of stochastic processes to fungal community assembly increased by 6.3% under biofertilizer treatment. Biofertilizer application reduced the average connectivity and density of microbial co-occurrence networks and changed some of the keystone genera. The results of this study may provide direction for the use of biofertilizers containing Streptomyces strains.

Does diet breadth affect the complexity of the phytophagous insect microbiota? The case study ofChrysomelidae.

SummaryChrysomelidae is a family of phytophagous insects with a highly variable degree of trophic specialization. The aim of this study is to test whether species feeding on different plants (generalists) harbour more complex microbiotas than those feeding on a few or a single plant species (specialists). The microbiota of representative leaf beetle species was characterized with a metabarcoding approach targeting V1–V2 and V4 regions of the bacterial 16S rRNA. Almost all the analysed species harbour at least one reproductive manipulator bacteria (e.g., Wolbachia, Rickettsia). Two putative primary symbionts, previously isolated only from a single species (Bromius obscurus), have been detected in two species of the same subfamily, suggesting a widespread symbiosis in Eumolpinae. Surprisingly, the well‐known aphid symbiont Buchnera is well represented in the microbiota of Orsodacne humeralis. Moreover, in this study, using Hill numbers to dissect the components of the microbiota diversity (abundant and rare bacteria), it has been demonstrated that generalist insect species harbour a more diversified microbiota than specialists. The higher microbiota diversity associated with a wider host‐plant spectrum could be seen as an adaptive trait, conferring new metabolic potential useful to expand the diet breath, or as a result of environmental stochastic acquisition conveyed by diet.

Cooperative Behaviors in Group-Living Spider Mites

Cooperative behaviors are evolutionary stable if the direct and/or indirect fitness benefits exceed the costs of helping. Here we discuss cooperation and behaviors akin to cooperation in subsocial group-living species of two genera of herbivorous spider mites (Tetranychidae), i.e., the largely polyphagous Tetranychus spp. and the nest-building Stigmaeopsis spp., which are specialized on grasses, such as bamboo. These spider mites are distributed in patches on various spatial scales, that is, within and among leaves of individual host plants and among individual hosts of single or multiple plant species. Group-living of spider mites is brought about by plant-colonizing foundresses ovipositing at local feeding sites and natal site fidelity, and by multiple individuals aggregating in the same site in response to direct and/or indirect cues, many of which are associated with webbing. In the case of the former, emerging patches are often composed of genetically closely related individuals, while in the case of the latter, local patches may consist of kin of various degrees and/or non-kin and even heterospecific spider mites. We describe and discuss ultimate and proximate aspects of cooperation by spider mites in host plant colonization and exploitation, dispersal, anti-predator behavior, and nesting-associated behaviors and conclude with theoretical and practical considerations of future research on cooperation in these highly rewarding model animals.

Floral Scents of a Deceptive Plant Are Hyperdiverse and Under Population-Specific Phenotypic Selection.

Floral scent is a key mediator in plant-pollinator interactions. However, little is known to what extent intraspecific scent variation is shaped by phenotypic selection, with no information yet in deceptive plants. In this study, we collected inflorescence scent and fruit set of the deceptive moth fly-pollinated Arum maculatum L. (Araceae) from six populations north vs. five populations south of the Alps, accumulating to 233 samples in total, and tested for differences in scent, fruit set, and phenotypic selection on scent across this geographic barrier. We recorded 289 scent compounds, the highest number so far reported in a single plant species. Most of the compounds occurred both north and south of the Alps; however, plants of the different regions emitted different absolute and relative amounts of scent. Fruit set was higher north than south of the Alps, and some, but not all differences in scent could be explained by differential phenotypic selection in northern vs. southern populations. This study is the first to provide evidence that floral scents of a deceptive plant are under phenotypic selection and that phenotypic selection is involved in shaping geographic patterns of floral scent in such plants. The hyperdiverse scent of A. maculatum might result from the imitation of various brood substrates of its pollinators.

Pollinator effectiveness is affected by intraindividual behavioral variation.

Variation in pollinator quality is fundamental to the evolution of plant-pollinator mutualisms and such variation frequently results from differences in foraging behavior. Surprisingly, despite substantial intraindividual variation in pollinator foraging behavior, the consequences for pollen removal and deposition on flowers are largely unknown. We asked how two pollen foraging behaviors of a generalist pollinator (Bombus impatiens) affect removal and deposition of heterospecific and conspecific pollen, key aspects of pollinator quality, for multiple plant species. In addition, we examined how bee body size and pollen placement among body parts shaped pollen movement. We manipulated foraging behavior types using artificial flowers, which donated pollen that captive bees then deposited on three recipient plant species. While body size primarily affected donor pollen removal, foraging behavior primarily affected donor pollen deposition. How behavior affected donor pollen deposition depended on the plant species and the quantity of donor pollen on the bee's abdomen. Plant species with smaller stigmas received significantly less pollen and fewer bees successfully transferred pollen to them. For a single plant species, heterospecific pollen interfered with conspecific pollen deposition, such that more heterospecific pollen on the bee's abdomen resulted in less conspecific pollen deposition on the flower. Thus, intraindividual variation in foraging behavior and its interaction with the amount and placement of acquired pollen and with floral morphology can affect pollinator quality and may shape plant fitness via both conspecific and heterospecific pollen transfer.

The septoria leaf blotch of wheat in Central Kazakhstan: prognosis, evaluation and monitoring with remotely sensed data

Fungal diseases represent a widely spread natural phenomenon affecting many of wild and domesticated plants. In nature, all plant species forms plant communities of a mixed character, and the spatial pattern of dominant species is usually irregular and spotted. Some species are impregnable to a certain infection, which provides a kind of natural barrier to the infection spread within the natural community. Under the agricultural environment, when the single plant species may occupy a huge area, the species-specific parasite takes a great advantage to develop focal outbreaks and fast spreading of the infection within the area. The concentration of vulnerable plants and the absence of natural barriers within the agricultural areas provokes outbreaks of fungal diseases, that may have highly harmful consequences and result in significant yield losses. One of the purposes of the satellite optical data is an operative, cost-effective diagnostic and, in combination with climatic datasets and crop rotation information, a prognosis of fungal disease appearance and severity. In this paper, we describe the system of prognostic and monitoring measures to control the fungal diseases of wheat in Central Kazakhstan with special attention to septoria leaf blotch. The prognostic procedure provides a map of the probability of septoria leaf blotch appearance. The prognosis takes into consideration the combination of three main variables: the model of ecological niche for Septoria, the presence of wheat residue, and Vegetation Condition Index counted for the late spring (May) of the current year. The new spectral index, introduced in this paper, is the core component of monitoring activity. The index is sensitive to septoria leaf blotch severity at middle to late (stages 8-11, accordingly Feekes growth stages) periods of wheat development. Several other indices (RETA, VSDI, vegetation indices) may be of help in providing information on the spatial unevenness of wheat crops that may indicate the presence of fungal infection.

Setting the evolutionary timeline: Tillandsia landbeckii in the Chilean Atacama Desert

The Chilean Atacama Desert is among the oldest deserts of the world. Here, Tillandsia landbeckii is forming a unique vegetation type known as Tillandsia lomas. This vegetation consists in its typical configuration of one single vascular plant species only and forms regular linear structures in a sloped landscape and is largely depending on fog occurrence as dominant source of water supply. Without developing a typical root system, there are only few other terrestrial Tillandsia species growing on bare sand in Chile and Peru such as T. marconae, T. virescens, T. purpureaor T. latifolia. Although phylogenetic evidence is limited, convergent evolution of this unique growth behavior is evident. The predominantly arid and hyper-arid climate exists since the Early Miocene, which raises the question about timing of T. landbeckii evolutionary history. Phylogenomic analyses using whole plastome sequence data highlight the onset of diversification in T. landbeckii approximately 500,000 years ago. We also demonstrate subsequent secondary genetic contact with T. purpurea during the Late Pleistocene using DNA sequence data and genome size estimates, which resulted into the formation of T. marconae.

PlantscRNAdb: A database for plant single-cell RNA analysis

PlantscRNAdb: A database for plant single-cell RNA analysis

Proteome analysis of bermudagrass stolons and rhizomes provides new insights into the adaptation of plant stems to aboveground and underground growth

As an important perennial warm-season turfgrass species, bermudagrass (Cynodon dactylon L.) forms underground-growing rhizomes and aboveground-growing stolons simultaneously, making it a fast propagating clonal plant with strong regeneration ability. In the current study, we compared the internode proteomes of rhizomes and stolons at the same developmental stage in the bermudagrass cultivar Yangjiang using iTRAQ. The results indicated that 228 protein species were differentially accumulated in the two specialized stems. In agreement with the different contents of starch, chlorophyll, anthocyanin and H2O2 in the two types of stems, photosynthesis and flavonoid biosynthesis were enriched with differentially accumulated protein species (DAPs) in stolons, whereas starch and sucrose metabolism, glycolysis, and H2O2 metabolism were enriched with DAPs in rhizomes. Burying stolons in the soil resulted in the gradual degradation of chlorophyll and anthocyanin, accumulation of starch, and increment of H2O2, which is similar to the physiological characteristics of rhizomes. These results collectively revealed that stolons and rhizomes of bermudagrass have significant differences at the proteome level and light might play important regulatory roles in the discrepancy of the proteome profiles and specialization of the two stems, providing new insights into the adaptation of plant stems to aboveground and underground growth. Biological significanceAs two types of specialized stems that grow underground and aboveground respectively, rhizomes and stolons play important roles in overwintering and ecological invasion of many perennial and clonal plants. However, because rhizomes and stolons rarely coexist in single plant species, the differences between the two stems remain unclear at the molecular level. In this study, through an iTRAQ comparative proteomic analysis, we reported the identification of 228 differentially accumulated protein species (DAPs) in rhizomes and stolons of bermudagrass for the first time. We found that the 228 DAPs were interconnected to form protein networks in regulating diverse cellular activities and biochemical reactions. We also observed that stolons growing underground showed similar physiological activities and DAP expression as those of underground-growing rhizomes, suggesting that light might play important regulatory roles in the specialization of stolons and rhizomes. These results expanded our understanding of the mysterious adaption of plant stems to different growth conditions.

Detecting de novo mitochondrial mutations in angiosperms with highly divergent evolutionary rates.

Although plant mitochondrial genomes typically show low rates of sequence evolution, levels of divergence in certain angiosperm lineages suggest anomalously high mitochondrial mutation rates. However, de novo mutations have never been directly analyzed in such lineages. Recent advances in high-fidelity DNA sequencing technologies have enabled detection of mitochondrial mutations when still present at low heteroplasmic frequencies. To date, these approaches have only been performed on a single plant species (Arabidopsis thaliana). Here, we apply a high-fidelity technique (Duplex Sequencing) to multiple angiosperms from the genus Silene, which exhibits extreme heterogeneity in rates of mitochondrial sequence evolution among close relatives. Consistent with phylogenetic evidence, we found that Silene latifolia maintains low mitochondrial variant frequencies that are comparable with previous measurements in Arabidopsis. Silene noctiflora also exhibited low variant frequencies despite high levels of historical sequence divergence, which supports other lines of evidence that this species has reverted to lower mitochondrial mutation rates after a past episode of acceleration. In contrast, S. conica showed much higher variant frequencies in mitochondrial (but not in plastid) DNA, consistent with an ongoing bout of elevated mitochondrial mutation rates. Moreover, we found an altered mutational spectrum in S. conica heavily biased towards AT→GC transitions. We also observed an unusually low number of mitochondrial genome copies per cell in S. conica, potentially pointing to reduced opportunities for homologous recombination to accurately repair mismatches in this species. Overall, these results suggest that historical fluctuations in mutation rates are driving extreme variation in rates of plant mitochondrial sequence evolution.