Tree Longevity Research Articles

Tree Longevity: Multifaceted Genetic Strategies and Beyond.

Old trees are remarkable for their ability to endure for centuries or even millennia, acting as recordkeepers of historical climate and custodians of genetic diversity. The secret to their longevity has long been a subject of fascination. Despite the challenges associated with studying old trees, such as massive size, slow growth rate, long lifespan and often remote habitat, accumulating studies have investigated the mechanisms underlying tree aging and longevity over the past decade. The recent publication of high-quality genomes of long-lived tree species, coupled with research on stem cell function and secondary metabolites in longevity, has brought us closer to unlocking the secrets of arboreal longevity. This review provides an overview of the global distribution of old trees and examines the environmental and anthropogenic factors that shape their presence. We summarize the contributions of physiological characteristics, stem cell activity, and immune system responses to their extraordinary longevity. We also explore the genetic and epigenetic 'longevity code', which consists of resistance and defense genes, DNA repair genes and patterns of DNA methylation modification. Further, we highlight key areas for future research that could enhance our understanding of the mechanisms underlying tree longevity.

Social and environmental outcomes of urban street tree bed stewardship

Abstract As projections of exponential urbanization persist, promoting the health of urban populations is one of the most urgent and challenging issues of the 21st century. By taking a planetary health approach and considering the reciprocal relationship between human health and the health of ecosystems, the integration of nature-based solutions into cities can address multiple urban challenges at once. Citizen stewardship of street trees and street tree beds is one such nature-based solution that challenges rapid urbanization while offering a healthier and greener future. Not only does citizen stewardship of street trees play a significant role in tree longevity, but our research suggests that the process of stewardship itself also positively impacts the health and wellbeing of stewards themselves. In this study, we sought to assess the motivations of street tree citizen stewards and the perceived social, environmental, and health effects of stewarding street tree beds in Freiburg, Germany. Based on a questionnaire-based survey and semi-structured interviews with tree stewards, we found that the most common motivations of citizen stewards were modeling positive environmental behavior as well as a desire to help the environment and one’s community. The perceived outcomes included a strong sense of place, a meaningful connection to nature, and the belief that stewarding a street tree bed is good for one’s mental health as well as the environment. Participants also considered street tree beds to be their personal gardens, suggesting that street tree beds may serve as restorative spaces that strengthen public health and social capital while sustaining urban greening. This case study supports and expands the scientific discourse of urban gardening while suggesting that citizen stewardship of street trees and tree beds offers myriad co-benefits for urban ecosystems and public health.

Ancient trees are essential elements for high-mountain forest conservation: Linking the longevity of trees to their ecological function

Mature forests and their extremely old trees are rare and threatened ancient vestiges in remote European high-mountain regions. Here, we analyze the role that extremely long-living trees have in mature forests biodiversity in relation to their singular traits underlying longevity. Tree size and age determine relative growth rates, bud abortion, and the water status of long-living trees. The oldest trees suffer indefectible age-related constraints but possess singular evolutionary traits defined by fitness adaptation, modular autonomy, and a resilient metabolism that allow them to have irreplaceable roles in the ecosystem as biodiversity anchors of vulnerable lichen species like Letharia vulpina. We suggest that the role of ancient trees as unique biodiversity reservoirs is linked to their singular physiological traits associated with longevity. The set of evolutionarily plastic tools that can only be provided by centuries or millennia of longevity helps the oldest trees of mature forests drive singular ecological relationships that are irreplaceable and necessary for ecosystem dynamics.

Tree Growth Enhancement Drives a Persistent Biomass Gain in Unmanaged Temperate Forests

AbstractWhile enhanced tree growth over the last decades has been reported in forests across the globe, it remains unclear whether it drives persistent biomass increases of forest stands, particularly in mature forests. Enhanced tree growth and stand‐level biomass are often linked with a simultaneous increase in density‐driven mortality and a reduction in tree longevity. Identifying empirical evidence regarding the balance between these processes is challenging due to the confounding effects of stand history, management, and environmental changes. Here, we investigate the link between growth and biomass via the negative relationship between average tree size and stand density (tree number per area). We find increasing stand density for a given mean tree size in unmanaged closed‐canopy forests in Switzerland over the past six decades and a positive relationship between tree growth and stand density across forest plots—qualitatively consistent with our simulations using a mechanistic, cohort‐resolving ecosystem model (BiomeE). Model simulations show that, in the absence of other disturbances, enhanced tree growth persistently increases biomass stocks despite simultaneous decreases in carbon residence time and tree longevity. However, the magnitude of simulated biomass changes for a given growth enhancement critically depends on the shape of the mortality functions. Our analyses reconcile reports of growth‐induced reductions of tree longevity with model predictions of persistent biomass increases, and with our finding of trends toward denser forests in response to growth—also in mature stands.

Whole genome sequencing and analysis of multiple isolates of Ceratocystis destructans, the causal agent of Ceratocystis canker of almond in California

Ceratocystis canker caused by Ceratocystis destructans is a severe disease of almond, reducing the longevity and productivity of infected trees. Once the disease has established in an individual tree, there is no cure, and management efforts are often limited to removing the infected area of cankers. In this study, we present the genome assemblies of five C. destructans isolates isolated from symptomatic almond trees. The genomes were assembled into a genome size of 27.2 ± 0.9 Mbp with an average of 6924 ± 135 protein-coding genes and an average GC content of 48.8 ± 0.02%. We concentrated our efforts on identifying putative virulence factors of canker pathogens. Analysis of the secreted carbohydrate-active enzymes showed that the genomes harbored 83.4 ± 1.8 secreted CAZymes. The secreted CAZymes covered all the known categories of CAZymes. AntiSMASH revealed that the genomes had at least 7 biosynthetic gene clusters, with one of the non-ribosomal peptide synthases encoding dimethylcoprogen, a conserved virulence determinant of plant pathogenic ascomycetes. From the predicted proteome, we also annotated cytochrome P450 monooxygenases, and transporters, these are well-established virulence determinants of canker pathogens. Moreover, we managed to identify 57.4 ± 2.1 putative effector proteins. Gene Ontology (GO) annotation was applied to compare gene content with two closely related species C. fimbriata, and C. albifundus. This study provides the first genome assemblies for C. destructans, expanding genomic resources for an important almond canker pathogen. The acquired knowledge provides a foundation for further advanced studies, such as molecular interactions with the host, which is critical for breeding for resistance.

Forgotten giants: Robust climate signal in pollarded trees

Tree ring records are among the most valuable resources to create high-resolution climate reconstructions. Most climate reconstructions are based on old trees growing in inaccessible mountainous areas with low human activity. Therefore, reconstruction of climate conditions in lowlands is usually based on data from distant mountains. Albeit old trees can be common in humanized areas, they are not used for climate reconstructions. Pollarding was a common traditional management in Europe that enabled trees to maintain great vitality for periods exceeding the longevity of unmanaged trees. We evaluate the potential of pollarded deciduous oaks to record past climate signal. We sampled four pollarded woodlands in Central Spain under continental Mediterranean climate. We hypothesized that pollarded trees have a strong response to water availability during current period without pollarding management, but also in the period under traditional management if pruning was asynchronous among trees. Moreover, we hypothesized that if climate is a regional driver of oak secondary growth, chronologies from different woodlands will be correlated. Pollard oaks age exceeded 500 years with a strong response to Standardized Precipitation-Evapotranspiration Index (SPEI) from 9 to 11 months. Climate signal was exceptionally high in three of the sites (r2 = 0.443–0.655) during low management period (1962–2022). The largest fraction of this climate signal (≈70 %) could be retrieved during the traditional management period (1902–1961) in the three sites where pollarding was asynchronous. Chronologies were significantly correlated since the 19th century for all the studied period, highlighting a shared climate forcing. We identified critical points to optimize pollard tree sampling schema. Our results show the enormous potential of pollarded woodlands to reconstruct hydroclimate conditions in the Mediterranean with a fine spatial grain. Studying pollarded trees is an urgent task, since the temporal window to retrieve the valuable information in pollarded trees is closing as these giants collapse and their wood rots.

Population change and nest tree longevity of a small-island population of Red-breasted Sapsuckers (Sphyrapicus ruber) breeding in old-growth temperate rainforest

Nous avons enregistré la taille de la population et l'utilisation des arbres de nidification des Pics à Poitrine Rousse (Sphyrapicus ruber) qui nichent dans la forêt pluviale tempérée côtière et ancienne de l'île East Limestone, à Haïda Gwaii, en Colombie-Britannique. La densité des populations sur cette île de 48 ha variait de 10 à 46 nids occupés/km2, avec une augmentation puis une diminution des effectifs de 1991 à 2005, suivie d'une augmentation progressive entre 2006 et 2020. La taille de la population n'a pas été affectée à la suite d'un chablis majeur qui, en 2010, a détruit environ un tiers du type de forêt préféré par l'espèce. Les oiseaux nicheurs ont continué à utiliser les arbres restants dans la zone de chablis, ce qui suggère que la rétention d'arbres morts isolés dans de petites ouvertures forestières peut fournir des sites de reproduction utiles pour les pics. Certains de ces arbres ont été utilisés jusqu'à 10 reprises et ont continué à être sélectionnés jusqu'à 21 ans après leur première utilisation, l'utilisation étant plus prolongée pour l'épicéa de Sitka (Picea sitchensis) que pour la pruche de l'ouest (Tsuga heterophylla). La durée maximale d'utilisation dépasse probablement 23 ans. Il y avait une tendance significative chez ces arbres à être utilisés au cours d'années consécutives. La modélisation de la disponibilité des arbres utilisés au moins une fois suggère qu' il y avait chaque année suffisamment d'arbres adéquats disponibles, et donc que la population n'était pas limitée par le manque de sites de nidification appropriés.

The Longevity of Fruit Trees in Basilicata (Southern Italy): Implications for Agricultural Biodiversity Conservation

In the Mediterranean basin, agriculture and other forms of human land use have shaped the environment since ancient times. Intensive and extensive agricultural systems managed with a few cultured plant populations of improved varieties are a widespread reality in many Mediterranean countries. Despite this, historical cultural landscapes still exist in interior and less intensively managed rural areas. There, ancient fruit tree varieties have survived modern cultivation systems, preserving a unique genetic heritage. In this study, we mapped and characterized 106 living fruit trees of ancient varieties in the Basilicata region of southern Italy. Tree ages were determined through tree ring measurements and radiocarbon analyses. We uncovered some of the oldest scientifically dated fruit trees in the world. The oldest fruit species were olive (max age 680 ± 57 years), mulberry (647 ± 66 years), chestnut (636 ± 66 years), and pear (467 ± 89 years). These patriarchs hold a unique genetic resource; their preservation and genetic maintenance through agamic propagation are now promoted by the Lucan Agency for the Development and Innovation in Agriculture (ALSIA). Each tree also represents a hub for biodiversity conservation in agrarian ecosystems: their large architecture and time persistence guarantee ecological niches and micro-habitats suitable for flora and fauna species of conservation significance.

Maximum tree lifespans derived from public-domain dendrochronological data

The public-domain International Tree-Ring Data Bank (ITRDB) is an under-utilized dataset to improve existing estimates of global tree longevity. We used the longest continuous ring-width series of existing ITRDB collections as an index of maximum tree age for that species and site. Using a total of 3,689 collections, we obtained longevity estimates for 237 unique tree species, 157 conifers and 80 angiosperms, distributed all over the world. More than half of the species (167) were represented by no more than 10 collections, and a similar number of species (144) reached longevity greater than 300 years. Maximum tree ages exceeded 1,000 years for several species (22), all of them conifers, whereas angiosperm longevity peaked around 500 years. Given the current emphasis on identifying human-induced impacts on global systems, detailed analyses of ITRDB holdings provide one of the most reliable sources of information for tree longevity as an ecological trait.

Land-use change and windstorms legacies drove the recolonization dynamics of laurel forests in Tenerife, Canary islands

Laurel forests are quite relevant for biodiversity conservation and are among the island ecosystems most severely damaged by human activities. In the past, Canary laurel forests have been greatly altered by logging, livestock and agriculture. The remains of laurel forests are currently protected in the Canary Islands (Spain). However, we miss basic information needed for their restoration and adaptive management, such as tree longevity, growth potential and responsiveness to natural and anthropogenic disturbances. Using dendrochronological methods, we studied how forest dynamic is related to land-use change and windstorms in two well-preserved laurel forests on Tenerife Island. Wood cores were collected from over 80 trees per stand at three stands per forest. We used ring-width series to estimate tree ages and calculate annual basal area increments (BAI), cumulative diameter increases, and changes indicative of released and suppressed growth. Twelve tree species were found in all stands, with Laurus novocanariensis, Ilex canariensis and Morella faya being the most common species. Although some individuals were over 100 years old, 61.8%–88.9% of the trees per stand established between 1940 and 1970, coinciding with a post-war period of land abandonment, rural exodus and the onset of a tourism economy. Some trees have shown growth rates larger than 1 ​cm diameter per year and most species have had increasing BAI trends over the past decades. Strong growth releases occurred after windstorms at both sites, but the effects of windstorms were site-dependent, with the 1958 storm affecting mainly the eastern tip of the island (Anaga massif) and the 1991 storm the western tip (Teno massif). Given the great ability of laurel forest trees to establish after land use cessation and to increase growth after local disturbances such as windstorms, passive restoration may be sufficient to regenerate this habitat in currently degraded areas.

Mrežaste stenice platana i hrasta

Provides an overview of Sycamore lace bug (Corythucha ciliata Say) and Oak lace bug (C. arcuata Say) based on literature data and monitoring during the period 2018-2022. The species have been present in insect fauna of Serbia over the past fifty years and ten years, respectively. Lace bugs are significant pests of sycamore and oak trees. Their damage manifests itself as premature desiccation and drop of leaf mass (premature defoliation), reducing air quality benefits of trees in urban areas and diminishing aesthetic function. Additionally, tissue injury and loss of nutrients can affect longevity of mature trees and reduce woody mass yield. Presents information on origin and geographic range, biology, damage and control of lace bugs.

Integrated Pest Management Strategies for Asian Citrus Psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) and Huanglongbing in Citrus for Sarawak, East Malaysia, Borneo.

Simple SummaryThe severe Asian form of huanglongbing is the most serious disease of citrus in Malaysia. It is caused by a phloem-limited bacterium ‘Candidatus Liberibacter asiaticus’ and transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama. Minimising the devastating impacts of the disease requires effective integrated pest management (IPM) programs to limit detrimental environmental and health consequences of over-reliance on synthetic pesticides. Key components of such programs include grower awareness, planting of pathogen-free trees, monitoring psyllid and disease incidence, removal of diseased trees, and judicious use of insecticides, mineral oils, and natural enemies to suppress incidence of the psyllid. Significant progress has been made towards implementing the programs.The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, transmits ‘Candidatus Liberibacter asiaticus’ (CLas), a phloem-limited bacterium associated with the severe Asian form of huanglongbing (HLB), and the most destructive disease of citrus. The pathogen and the psyllid, both of South Asian origin, are now widespread in citrus regions of Asia and the Americas. There is no cure for the disease. Application of synthetic pesticides, in some instances more frequently than fortnightly, to minimise incidence of ACP in citrus orchards, has not prevented inevitable impacts of the disease in regions of Asia where CLas is present. Despite the inevitable spread of the disease, significant progress has been made in Sarawak since the mid-1990s towards effectively implementing integrated pest management (IPM) programs for stemming the impact of the disease and detrimental consequences of over-reliance on synthetic pesticides. Growers are encouraged to plant pathogen-free trees, remove diseased trees, monitor incidence of the psyllid, and to use pesticides judiciously to reduce their detrimental impacts on natural enemies. Knowledge has been enhanced through research on seasonal incidence of the psyllid, use of mineral oils, development of protocols and iodine–starch test kits for detecting infected trees, PCR for confirming the presence of CLas in symptomatic leaves, methods for monitoring incidence the psyllid, and training extension staff and growers. However, major impediments to increasing the average longevity of trees beyond <5 years in poorly managed orchards, based on marcotting (air layering), and >12 years in well-managed orchards, based on pathogen-free trees, still need to be addressed. These include grower knowledge, marcotting, aggressive marketing of synthetic pesticides, high prices of mineral oils, spray application procedures, and better reliance on natural enemies of the psyllid.

Large old trees increase growth under shifting climatic constraints: Aligning tree longevity and individual growth dynamics in primary mountain spruce forests.

In a world of accelerating changes in environmental conditions driving tree growth, tradeoffs between tree growth rate and longevity could curtail the abundance of large old trees (LOTs), with potentially dire consequences for biodiversity and carbon storage. However, the influence of tree-level tradeoffs on forest structure at landscape scales will also depend on disturbances, which shape tree size and age distribution, and on whether LOTs can benefit from improved growing conditions due to climate warming. We analyzed temporal and spatial variation in radial growth patterns from ~5000 Norway spruce (Picea abies [L.] H. Karst) live and dead trees from the Western Carpathian primary spruce forest stands. We applied mixed-linear modeling to quantify the importance of LOT growth histories and stand dynamics (i.e., competition and disturbance factors) on lifespan. Finally, we assessed regional synchronization in radial growth variability over the 20th century, and modeled the effects of stand dynamics and climate on LOTs recent growth trends. Tree age varied considerably among forest stands, implying an important role of disturbance as an age constraint. Slow juvenile growth and longer period of suppressed growth prolonged tree lifespan, while increasing disturbance severity and shorter time since last disturbance decreased it. The highest age was not achieved only by trees with continuous slow growth, but those with slow juvenile growth followed by subsequent growth releases. Growth trend analysis demonstrated an increase in absolute growth rates in response to climate warming, with late summer temperatures driving the recent growth trend. Contrary to our expectation that LOTs would eventually exhibit declining growth rates, the oldest LOTs (>400 years) continuously increase growth throughout their lives, indicating a high phenotypic plasticity of LOTs for increasing biomass, and a strong carbon sink role of primary spruce forests under rising temperatures, intensifying droughts, and increasing bark beetle outbreaks.

Population and conservation genetics using RAD sequencing in four endemic conifers from South America

The emblematic conifer flora of Chile has experienced wide-scale habitat loss and fragmentation. Coupled with the complex topography of the region, this leads to a prediction of high levels of genetic drift and isolation resulting in strong population differentiation, and the potential for negative genetic consequences. To address the degree to which these predictions are realised, we conducted a comparative population genetic survey in four endemic conifers from South America, each of conservation concern and with a restricted distribution area. Between seven and ten populations per species were sampled, covering their entire natural distribution in Chile. We used restriction site-associated DNA markers (RAD-seq), with de novo assembly and optimisation, to accommodate the large and complex genome of conifers. The main finding was low levels of genetic structure in all four conifer species (FST = 0.017–0.062). This pattern was strikingly consistent across all four species. These results are likely due to the extreme longevity of individuals restricting divergence due to genetic drift. Thus, despite the currently highly fragmented ranges of these conifer species, we did not detect evidence for high levels of population differentiation and genetic isolation. This suggests some resilience to negative genetic impacts of habitat fragmentation, and the longevity of the individual trees may provide considerable buffering capacity. We recommend follow-up studies focusing on genotyping the seedling generation, to assess whether there is any evidence for the early warning of genetic isolation and/or elevated inbreeding in the currently established cohorts.

Analyses of gene copy number variation in diverse epigenetic regulatory gene families across plants: Increased copy numbers of BRUSHY1/TONSOKU/MGOUN3 (BRU1/TSK/MGO3) and SILENCING DEFECTIVE 3 (SDE3) in long-lived trees

Long-lived trees experience high risk of damage due to the various types of stresses over their lifespans. Epigenetic regulation is involved in gene regulation, genome integrity, and inhibition of exogenous genetic elements, which are functions important for long-term survival. To narrow down the candidate genes related to tree longevity among diverse epigenetic regulatory genes, it is necessary to identify epigenetic regulatory genes with increased copy number in long-lived tree species as compared to in short-lived annual and perennial herb species. In the present study, to find out the epigenetic regulatory genes with increased copy number in tree species as compared to in annual and perennial herb species, we conducted the systematic comparison of copy number variation in 121 gene families involved in various epigenetic regulatory pathways across 85 plant species with different lifespans using a genome database. Among these 121 gene families, the gene family encoding BRUSHY1/TONSOKU/MGOUN3 (BRU1/TSK/MGO3) and that encoding SILENCING DEFECTIVE 3 (SDE3) were found to exhibit significantly higher copy number of genes in tree species than in both perennial and annual herb species. BRU1/TSK/MGO3 is involved in chromatin modifications and plays an important role in the maintenance of meristems, genome integrity, and the inheritance of chromatin states. SDE3 is involved in RNA silencing and has an important role in antiviral defense through posttranscriptional gene silencing. The systematic comparison of copy number variation in diverse epigenetic regulatory gene families among plant species can find out epigenetic regulatory genes with increased copy number in long-lived tree species and enhance subsequent studies for understanding the relationship between epigenetic regulation and tree longevity.

Assessment of Wound Recovery and Radial Growth 10 Years after Forest Operations in Hardwood Stands

Damage to the residual stand caused by forest operations can have detrimental impacts on the biological processes of stand growth. This study shows the details from monitoring damages related to manual motor ground-based timber operations in a mountain mixed hardwood forest. The harvesting system was cut-to-length, and logs were extracted by wheeled cable-skidders. Data were collected from the remaining trees immediately after logging and 10 years after the logging session. The parameters assessed included stem injury, radial growth increment and wound healing rate for five hardwood species of commercial interest. The number of injured trees represented 15% of the residual stand, 23% of the wounds were related to the felling operation and 76% to extraction. Wound height, wound size and damage to bark, due to felling, were larger than those in extraction, while wound width and damages to cambium and wood caused by extraction were larger than those triggered by felling. Ten years after harvesting, average longitudinal and radial growth increments were reduced by 38% and 24%, respectively. Wound healing rates ranged from 12.90 mm yr−1 for extraction wounds to 19.70 mm yr−1 for felling ones within 10 years. On average 73% of all wounds were still unrecovered and 17% of these were decayed, while only 10% were fully healed within a 10-year recovery period. The analysis showed that the best recovering performance among damaged trees was mostly achieved in shade-intolerant species with a diameter less than 40 cm, located in the dominant canopy layer with a wound size smaller than 100 cm2. In addition to the significant effect on log quality, the ecological longevity of residual trees has major implications for pre-planning harvesting operations that can preserve the quality and value of residual trees. Understanding the damage inflicted upon residual trees is essential to reduce economic losses, improve planning of harvest operations and, ultimately, ensure a sustainable harvest of mixed hardwood stands in mountain regions.

Рост и состояние смешанных древостоев лесных насаждений Каменной Степи

By now, a vast amount of experimental material has been accumulated in the field of protective afforestation of the Central Chernozem Region of Russia, which allows estimating the stability and longevity of various trees and shrubs in different environmental conditions. Good growth and high vitality of woody vegetation largely depend on growing conditions and are determined primarily by the relationship between species (individuals within a species) when they are placed in the forest area and the type of terrain. The researchdifferent combinations in tree and shrub mixing schemes and unequal location by types of terrain. The study was carried out in mature (115–118-year-old) forest strips laid out by the staff of the Kamennaya Steppe experimental forestry G.F. Morozov and N.A. Mikhailov on the territory of the Kamennaya Steppe (Voronezh region, Talovsky district) using archival materials, scientific works of the authors of this article and the employees of the Department of Agroforestry. A comparative analysis of the materials of forest survey work carried out in protective forest plantations created according to the tree-shrub type of mixing on different types of terrain revealed an excess of biometric indicators of tree species growing on the upland type of terrain over those on the slope. It is shown that the initial percentage of participation of English oak is a significant, but not always decisive factor in the creation of oak plantations. They can also be grown with a smaller proportion of this species in the culture, but in this case, timely thinning will be of paramount importance. Over time, there have been significant changes in the composition of plantations, the number of trees and their valuation indicators. There are no viable ash and elm specimens left in the upper tier of the stands. They are severely damaged by stem pests. Certain tree species are damaged by the following pests: common ash by large ash bark beetle (Hylesinus crenatus) and ash bark beetle (Hylesinus fraxini); elm species by cambium-feeding beetles (large elm bark beetle (Scolytus scolytus), European elm bark beetle (Scolytus multistriatus), and pygmy elm bark beetle (Scolytus pygmaeus); English oak by gold pit oak splendour beetle (Chrysobothris affinis), oak borer (Agrilus angustulus), longhorn beetle (Plagionotus detritus), and European oak bark beetle (Scolytus intricatus). The predominant number of trees of all tree species belongs to the categories of limited viable and inviable.

Copy number analyses of DNA repair genes reveal the role of poly(ADP-ribose) polymerase (PARP) in tree longevity

SummaryLong-lived organisms are exposed to the risk of accumulating mutations due to DNA damage. Previous studies in animals have revealed the positive relationship between the copy number of DNA repair genes and longevity. However, the role of DNA repair in the lifespan of plants remains poorly understood. Using the recent accumulation of the complete genome sequences of diverse plant species, we performed systematic comparative analyses of the copy number variations of DNA repair genes in 61 plant species with different lifespans. Among 121 DNA repair gene families, PARP gene family was identified as a unique gene that exhibits significant expansion in trees compared to annual and perennial herbs. Among three paralogs of plant PARPs, PARP1 showed a close association with growth rate. PARPs catalyze poly(ADP-ribosyl)ation and play pivotal roles in DNA repair and antipathogen defense. Our study suggests the conserved role of PARPs in longevity between plants and animals.

Population and comparative genetics of thermotolerance divergence between yeast species.

Many familiar traits in the natural world—from lions’ manes to the longevity of bristlecone pine trees—arose in the distant past, and have long since fixed in their respective species. A key challenge in evolutionary genetics is to figure out how and why species-defining traits have come to be. We used the thermotolerance growth advantage of the yeast Saccharomyces cerevisiae over its sister species Saccharomyces paradoxus as a model for addressing these questions. Analyzing loci at which the S. cerevisiae allele promotes thermotolerance, we detected robust evidence for positive selection, including amino acid divergence between the species and conservation within S. cerevisiae populations. Because such signatures were particularly strong at the chromosome segregation gene ESP1, we used this locus as a case study for focused mechanistic follow-up. Experiments revealed that, in culture at high temperature, the S. paradoxus ESP1 allele conferred a qualitative defect in biomass accumulation and cell division relative to the S. cerevisiae allele. Only genetic divergence in the ESP1 coding region mattered phenotypically, with no functional impact detectable from the promoter. Our data support a model in which an ancient ancestor of S. cerevisiae, under selection to boost viability at high temperature, acquired amino acid variants at ESP1 and many other loci, which have been constrained since then. Complex adaptations of this type hold promise as a paradigm for interspecies genetics, especially in deeply diverged traits that may have taken millions of years to evolve.

СОВРЕМЕННАЯ ГЕНОСИСТЕМАТИКА И БИОЛОГИЧЕСКИЕ ОСОБЕННОСТИ ЕСТЕСТВЕННО РАСТУЩИХ И ИНТРОДУЦИРОВАННЫХ ВИДОВ РОДА QUERCUS

Decoding and annotation of the Oak genome has clarified the taxonomy of the genus Quercus and opens up new possibilities for researchers and foresters for selection and assessment of the evolutionary development of forest formers and forest communities. The purpose of the review was to analyze modern genosystematics, as well as biological characteristics of naturally growing and introduced species of the genus Quercus in Central Russia. For the species Quercus robur, the genome was sequenced, assembled and annotated; the genome decoding made it possible to find out that the longevity and resistance of oak trees is largely based on duplication of R genes for resistance to pathogens, as well as to confirm the accumulation and transmission of somatic mutations in the apical meristems of the shoots. Genetic analysis made it possible to clarify the phylogenetic relationships and divide the genus into the subgenera Euquercus (from 320 to 354 species) and Cyclobalanopsis (76 species) and 6 sections, the main of which are: the Erythrobalanus group (red oak), the Lepidobalanus (white oak), and the Cerris group. The genus Quercus is an important forest producer in the Northern Hemisphere. Considering its ecological nature (the dominance, diversity and development of the data of their phylogenetic, genomic and ecological resources of an important model clade), the oak is a model object of scientific research. Flexible phenology and features of the water regime made it possible to adapt to a wide range of habitat conditions, to form climatypes within and between species, contributing to their high abundance and diversity. Oaks as long-lived plants represent a unique model for the formation of sustainable forest communities; the diversity of species allows them to be introduced into regions of different climatic and ecological factors. In most cases, oaks are ecological dominants, so discoveries at the genome level will be relevant at the level of forest ecosystems and may be the key to solving the problems of sustainability and productivity of oak forests. The review presents modern data on the division of the genus Quercus into subgenera and clades, genetic maps, and the basics of oak longevity. The data on the biology of the genus and species of Central Russia are presented, as well as ecological significance of the genus and the possibility of using trees in various spheres of human activity