Wednesday, July 03, 2024

 

Huge study identifies suicide risk factors to improve preventions


In the largest study of its kind, scientists at the University of Warwick have investigated a range of contributing risk factors for suicide – helping to identify individuals who might benefit from interventions



UNIVERSITY OF WARWICK





In the largest study of its kind, scientists at the University of Warwick have investigated a range of contributing risk factors for suicide – helping to identify individuals who might benefit from interventions.

The behavioural and biological predictors, include elevated white blood cells, neuroticism, childhood experiences and reduced grey matter in the brain. Previous research had focussed on much smaller sample groups and on fewer risk factors – potentially overlooking some impactors.

It is hoped that the research will tackle the global challenge of suicide – a leading cause of deaths worldwide. According to the World Health Organisation, more than 700 000 people die from suicide every year.

The study also helps to identify individuals most at risk, who could be targeted for preventive treatments – such as those suffering mental distress and feelings of worthlessness – by GPs. By using data from more than 500,000 participants from the UK biobank, a population-based study cohort, its broader approach provides a wider understanding of risk factors, to contribute to more effective preventions.

The team used a variety of methods investigate suicidal risk factors, including brain scans, blood samples and questionnaires. This led to more than 400 behaviours (including smoking), biological factors (such as amount of grey matter in the brain), and genetics being investigated. A type of artificial intelligence known as machine learning was used to comprehensively analyse the huge dataset.

Factors which associated with suicide included suffering from mental distress, neuroticism, lower grey matter in the brain, size of the emotional regulation areas of the brain and increased white blood cells. The study highlighted how these vastly different influencers could contribute to suicidal behaviours.

Study author Professor Jianfeng Feng, Department of Computer Science, University of Warwick, said: “Our study developed a machine learning model based on behavioural factors. The top 16 predictors showed high accuracy in distinguishing individuals, both with and without suicide attempts. This may be useful in identifying people at high risk of suicide in the future.

“The top behavioural predictors, in addition to the few related to mental illness and depression, are childhood experiences and survivors of sexual assault. These factors provide potential actionable targets for clinicians to develop better prevention strategies.”

Co-Author Dr Bei Zhang, Fudan University, added: “Suicide is a major public health concern that arises from a complex interplay of various factors. While existing research has often focused on a narrow set of behavioural hypotheses often within small clinical samples, our study fills the gap by systematically assessing a broad range of risk factors for suicide attempts in large, community-based samples. By identifying and understanding these factors, we hope to improve predictive models, better identify those at risk, and inform more effective prevention and intervention strategies, ultimately reducing the global burden of suicide.”

Professor Barbara Sahakian from the University of Cambridge commented, "Suicide is a tragic loss of life, but it also leaves family and friends devastated. By identifying key risk factors for suicide, this study brings us closer to understanding how we might identify vulnerable individuals and intervene to save lives."

For future research, the team emphasised the need for a similar determination of the risk factors for suicide in adolescents, especially as suicide in adolescence is on the increase.

Read the study here: https://www.nature.com/articles/s41562-024-01903-xLink opens in a new window


Notes to Editors

The University of Warwick signed a Memorandum of Understanding with Fudan University in 2022 and the two Universities work together designing and developing new research projects and run staff and student exchanges.

The UK Biobank is a population-based cohort comprising over 500,000 participants in the United Kingdom aged between 37 and 73 years and recruited between 2006 and 2010 (http://www.ukbiobank.ac.uk).
 

 

RecombinHunt: predicting new pandemics through data analysis



POLITECNICO DI MILANO





Milan, July 2, 2024 - Combating future pandemics through data analysis of recombinant virus genomes. A study published in the prestigious journal Nature Communication presents the promising results of RecombinHunt, a new data-driven method developed by the Department of Electronics, Information and Bioengineering of the Politecnico di Milano and the University of Milan, which can identify, with high accuracy and computational efficiency, recombinant SARS-CoV-2 genomes with one or two breakpoints.

Recombination, that is, the composition of two or more viral genomes to form a new genome, is an efficient molecular mechanism for virus evolution and adaptation.

Exploiting the incentive of the COVID-19 pandemic, several methods have been proposed to detect recombinant genomes of SARS-CoV-2 virus; however, so far, none has been able to faithfully confirm the manual analyses of experts in the field.

ReconbinHunt shows high specificity and sensitivity, is more effective than all other methods already developed, and faithfully confirms manual expert analyses.

The method, developed under the PRIN PNRR 2022, SENSIBLE project (Small-data Early warNing System for viral pathogens In puBLic hEalth), also identifies recombinant viral genomes from the recent monkeypox epidemic with high concordance with analyses manually curated by experts, suggesting that the approach is robust and can be applied to any epidemic or pandemic virus, representing an important tool to combat future pandemics.

Prof. Stefano Ceri notes that "the research was possible thanks to the extraordinary contribution of laboratories from all over the world, which made more than 15 million viral sequences available to the international community." Dr. Anna Bernasconi, SENSIBLE project leader, notes, "Our goal is to build warning tools to anticipate and combat new viral epidemics and pandemics."

"The study demonstrates how the development of innovative and efficient computational methods allows us to more accurately and rigorously appreciate the evolution of pathogens, and any implications for human health," adds Prof. Matteo Chiara, professor of Molecular Biology at the University of Milan and co-leader of the SENSIBLE project.

A main contribution to the study was given by Dr. Tommaso Alfonsi, who recently earned a doctorate "cum laude" in Information Engineering, presenting this and other timely research.

 

HKUST identifies novel host factors that facilitates SARS-CoV-2 entry


Paving new therapeutic strategies for COVID-19



HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY

Prof. GUO Yusong (center) and his research team at HKUST 

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PROF. GUO YUSONG (CENTER) AND HIS RESEARCH TEAM AT HKUST

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CREDIT: HKUST



A research team led by Prof. GUO Yusong, Associate Professor of the Division of Life Science at the Hong Kong University of Science and Technology (HKUST), recently made a novel discovery related to the coronavirus (SARS-CoV-2) that causes COVID-19. The team identified new host factors that interact with the receptor binding domain of the SARS-CoV-2 spike protein to promote viral entry. This finding offers valuable mechanistic insights and potential therapeutic strategies against SARS-CoV-2 infection.

It is generally believed that SARS-CoV-2 enters host cells through the interaction between its spike protein's receptor-binding domain (CoV2-RBD) and the host cell receptor ACE2, facilitating viral invasion. However, most evidence is based on the overexpression of ACE2 to promote viral entry, with few studies conducted on whether completely knocking out ACE2 inhibits viral entry. To address this, the HKUST research team, led by Prof. Guo, in collaboration with research teams from the University of Hong Kong (HKU) and the Hong Kong Polytechnic University (PolyU), has identified other novel surface-located host factors, apart from ACE2, that also bind to CoV2-RBD using the GST pull-down method.

The experiment demonstrates that among the factors, one in particular called SH3BP4, regulates the internalization of CoV2-RBD and mediates the entry of SARS-CoV-2 pseudovirus in a manner that is dependent on integrins and the clathrin, but not on ACE2, implying that SH3BP4 promotes viral entry via the endocytic pathway. Many identified factors, including SH3BP4, ADAM9, and TMEM2, show a stronger affinity for CoV2-RBD compared to the RBD of the less infectious SARS-CoV, indicating their specific usage for SARS-CoV-2.  Moreover, this study uncovers factors that preferentially bind to the RBD of the SARS-CoV-2 Delta variant, potentially enhancing its entry.

“These findings identify novel host cell surface factors involved in the invasion of SARS-CoV-2 and highlight the crucial role of integrins in mediating viral internalization, establishing new research foundations for treating COVID-19,” Prof. Guo said.

The study was recently published in the international academic journal, Journal of Biological Chemistry. The research team also consists of Prof. CHEN Honglin from Department of Microbiology at HKU; and Prof. YAO Zhongping, from Department of Applied Biology and Chemical Technology at PolyU; and their team members.

A model demonstrating how SARS-CoV-2 gains entry into host cells

CREDIT

HKUSTJOURNAL

ARACHNOLOGY

Invasive brown widow spiders host novel bacteria related to chlamydia




BEN-GURION UNIVERSITY OF THE NEGEV





SDE BOKER, Israel, July 2, 2024 – Invasive brown widow spiders across three continents were highly infected with a single strain of Rhabdochlamydia, a bacterium that is related to major pathogens of humans and animals, including chlamydia. A bite from these spiders, however, will not infect people with chlamydia. Up until now, Rhabdochlamydia was found in only a few organisms – a tick, an isopod, a cockroach, and one other spider – and even then, was a rare occurrence in all these organisms.

Dr. Monica Mowery and colleagues at Ben-Gurion University of the Negev compared microbial communities in populations of brown widow spiders collected in South Africa (the likely native range of the spider) and invasive populations in Israel and the United States. The overwhelmingly predominant bacteria, Rhabdochlamydia, was found in 86% of spiders surveyed. It was also found in the female spider’s eggs, indicating that mother spiders transmit the bacteria to their offspring.

“Our results suggest that this dominant, widely prevalent chlamydial bacteria has an important role in the invasive brown widow spider,” explained Dr. Monica Mowery, an assistant professor at the City University of New York and a former post-doctoral researcher at BGU.

The study was published recently in Scientific Reports.

Characterizing potentially important and widespread bacterial symbionts is a step towards understanding their relevance to ecological interactions and responses to rapid environmental changes. The high prevalence of Rhabdochlamydia in all spider populations tested suggests it may have an important functional role and could contribute to the spider’s invasion success.

The brown widow spider, Latrodectus geometricus, is an urban invasive species that outcompetes native spider species found in warm climates worldwide. These spiders have neurotoxic venom and can be dangerous to young children and the elderly.

Microbial associates can influence a species’ invasive spread and success in a new environment and can shift or be lost during the invasion process. The South African brown widow spiders had overall more distinct strains of bacteria compared to newer arrivals in Israel, where brown widows were first found in Tel Aviv in 1980 and in the United States, where spiders expanded from southern Florida in the 2000s. This higher microbial diversity supports the idea that the invasive brown widow spider originated in southern Africa.

Additional researchers included Prof. Yael Lubin and Prof. Michal Segoli from Ben-Gurion University of the Negev, Prof. Jennifer White, Dr. Eric Chapman, and Laura Rosenwald from the University of Kentucky, Thembile Khoza from the South African National Biodiversity Institute, and Robin Lyle from the Agricultural Research Council, South Africa.

Funding was provided by a Zuckerman STEM Postdoctoral fellowship to Dr. Monica Mowery and by a National Science Foundation grant to Prof. Jennifer White.

 LEOPARD'S VS HYENAS

Spotted apex predator being pressured by spotted pack hunters – and it's our fault



UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE
Images from camera traps 

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IMAGES FROM CAMERA TRAPS IN UDZUNGWA. FROM THE LEFT: FEMALE LEOPARD, HYENA, MALE LEOPARD

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CREDIT: RASMUS W. HAVMĂ˜LLER




Who’s stronger? A solitary leopard or cackle of hyenas? And which is best at getting along with humans?

University of Copenhagen researchers closely studied this in a large East African natural area surrounded by rural settlements. The study demonstrates that the presence of humans has a direct impact on the competitive relationship between the two large predator species: leopards (Panthera pardus) – the iconic spotted feline and the spotted hyena (Crocuta crocuta) – a kleptoparasite and pack hunter known for its comical appearance and characteristic 'laugh'.

"We humans continue eating our way into the little bit of wilderness left in the world. As we do, we impact wildlife. This study demonstrates that human disturbance upsets the balance between competing species and that this advantages hyenas," says Rasmus W. Havmøller, the study’s first author and a postdoc at the University of Copenhagen’s Natural History Museum of Denmark.

For months, Havmøller have been using camera traps to observe the dynamics between hyenas and leopards living in Tanzania’s Udzungwa Mountains – an approximately 2,000 km2 national park that is completely surrounded by agricultural and populated areas. The study is the first to combine camera observations of large predators over both time and space in a single analysis.

While the hyena as a species seems to be increasing in numbers, the population of leopards has been in significant decline for decades, both in Africa and worldwide. Since hyenas are the leopards' only competitor in this particular natural area, the ability of the two species to coexist is important for their survival. And here, the local population is an important factor:

"As the local people definitely don’t' like leopards, the leopards retreat as far away from humans as possible. Hyenas, on the other hand, benefit from the fact that humans don’t feel threatened by or pursue them. Consequently, hyenas live in close to human populations and may even exploit humans as shields against the leopards," says Havmøller.

"But the areas nearest to humans are also the areas with the most prey. And as hyenas assert dominance over these areas, it increases their ability to outcompete leopards and potentially threaten the leopard's adaptability," adds Havmøller.

Size matters

The researchers' observations confirm that size matters. While male leopards, which are larger, retain their dominance over hyenas, the situation is different for female leopards, which are smaller.

"Even though the male leopards are the ones in charge, the hyenas aren’t exactly scared off by them. They simply hang out in the background – probably to follow the leopards and steal their prey. But the physical inferiority of the hyenas seems to be compensated for in the areas closest to humans, because male leopards pull out," says Rasmus W. Havmøller, who continues:

"Female leopards, on the other hand, completely change their behavior when hyenas are in the area. They become diurnal, whereas hyenas are primarily nocturnal. This is probably because female leopards are smaller than hyenas, and that they will likely lose in any fight over prey."

Overall, the study shows that the hyenas benefit from living near humans.

"This suggests that the hyena's ability to adapt to areas of human activity may strengthen their overall success as a species and their competitive advantage over other large predators as we humans disturb more and more nature," says Havmøller.

When leopards are pressured, cascade effects may follow

According to the researcher, the shift in female leopard hunting patterns may have negative consequences:

"If you open up for more tourism and build more roads in the national park, the female leopards will be pressured immediately. They aren’t able to differentiate between safari tourists – who are most active during the day – and poachers. In time, they will probably learn that safari guests aren’t dangerous. But if there is a large and rapid influx into the area, you will probably see a decline in their population," says Rasmus W. Havmøller.

If leopards are seriously pressured out of the food chain, one should expect the emergence of what are known as cascade effects in the ecosystem:

"Plucking a large predator like leopards out of a food chain, which can be the ultimate consequence of human disturbances, may have very violent effects. Populations of other species, such as certain monkeys, whose populations are kept in check by leopards, will suddenly become too large and change the balance of the entire ecosystem," says the researcher.

As such, Havmøller hopes that the study will serve to encourage restraint when it comes to managing wilderness areas.

"Our results clearly indicate that human disturbances can change the competitive relationship between important predators. So, I hope that considerations will be made when expanding activities in wilderness areas, so as to roll them out slowly and give animals a chance to adapt. Furthermore, it would be good if the effects of human disturbances were monitored in more places using camera traps," concludes Rasmus W. Havmøller.

 

 

HYENAS VS. LEOPARDS 

  • Leopards are unpopular among local people in many places because they may hunt livestock and attack humans. Hyenas, on the other hand, "clean up" by eating sick or dead livestock and don’t pose a problem for humans.
  • Female leopards (approx. 20-43 kg.) are about half the size of male leopards (approx. 51-72 kg). Hyenas are in the middle in terms of weight (approx. 48-56 kg).
  • Leopards are solitary hunters, whereas hyenas hunt in large cackles (clans), which can be an advantage for hyenas in confrontations with leopards.
  • Hyenas are kleptoparasites that regularly steal the prey of other carnivores – including leopards.
  • Leopards on the other hand, are masterful tree-climbers, which allows them to protect their prey from hyenas.

 

ABOUT THE STUDY

  • The researchers behind the study are: Rasmus W. Havmøller and Linnea W. Havmøller from the Natural History Museum of Denmark, University of Copenhagen; Arielle W. Parsons from Lincoln Park Zoo, USA and Roland Kays from North Carolina State University, USA.
  • The study has been published in the scientific journal Ecosphere.
  • The research is supported by the ERC under the EU’s Horizon 2020 programme.

  

Map of Udzungwa Mountains, Tanzania

CREDIT

(map from the scientific article)

ALGAE HAVE EARS

Study illuminates cues algae use to ‘listen’ to their environment



BIGELOW LABORATORY FOR OCEAN SCIENCES
C. paradoxa 

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A SCANNING ELECTRON MICROSCOPE IMAGE OF C. PARADOXA, THE SPECIES OF GLAUCOPHYTE THE STUDY’S AUTHORS EXAMINED (COURTESY OF JOHN BURNS).

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CREDIT: JOHN BURNS, BIGELOW LABORATORY FOR OCEAN SCIENCES




Plants have long been known to release chemicals to respond to stress and relay information to their neighbors. A team of scientists from Bigelow Laboratory have shown that glaucophytes, a small group of single-celled algae distantly related to plants, appear to have the same penchant for chemical communication. This suggests that the ability to use chemical cues in this way may not be unique to complex life as once thought, but rather evolved further back on the tree of life.

“We’re looking at this organism that shares ancestry with plants, and uses a communication process that people once thought only plants used,” said Senior Research Scientist John Burns, a co-author on the study. “It’s possible that many branches of life  started with similar tools for communication but then diverged in the particular genetic way they do it.”

Discovering how cell communication works in new lineages helps scientists understand how these abilities emerged and have changed over time. Microalgae, like glaucophytes, are also essential to biogeochemical cycling in aquatic systems so understanding them is essential for predicting how the larger ecosystem functions, especially in stressful situations.

“The underlying communication process used by plants and glaucophytes is similar, and they’re based on the same basic components of life,” said Baptiste Genot, a former postdoctoral researcher at Bigelow Laboratory and the study’s lead author. “But going beyond plants to understand how single cells like these algae carry these processes out is really paving a new trail.” 

Their results were recently published in The Journal of Eukaryotic Microbiology.

Scientists have long understood that plants emit informational molecules, like hormones and other organic compounds, as a way to communicate information and adapt to stressful situations like changes in temperature or exposure to toxins. But there’s far less information on the strategies used by microalgae, despite them being the most abundant primary producers in aquatic systems.

That includes glaucophytes, one of the three main lineages in what’s called the Archaeplastida. Organisms in this group, including plants, as well as green and red algae, are known to have a common ancestor over a billion years ago. Understanding commonalities between the complex communication strategies used by these different organisms can help scientists map the timeline of when lineages branched off from each other. It can also help them better understand how the tools used for photosynthesis evolved.

“Glaucophytes are this other branch of life that developed chloroplasts at the same time as plant ancestors did, but ran with it in a whole different evolutionary direction,” Burns said. “So, you can use these comparisons to answer really basic questions about photosynthesis across all branches of life.”

The researchers focused on one species of glaucophyte, called Cyanophora paradoxa. They found that, in response to external stressors like changing light, C. paradoxa produces potent hormones like ethylene, which plays a key role in fruit ripening and is known to be released by plants in response to stress. When the team supplied the algae with a chemical that’s a precursor to ethylene, they found that the glaucophytes produced large quantities of the hormone, and slowed down their growth rate in response.

“If you looked at the genes plants have, you would never think that glaucophytes could use these same signaling pathways, because they just don’t have the same ‘parts,’” Burns said. “We often use plants as our baseline for photosynthetic life, but, in this story, they’re the ‘weirdos’ who took off in a different evolutionary direction. Glaucophytes may have more in common with other algae than plants do when it comes to these behaviors.”

This study provides the first evidence of glaucophytes releasing hormones as a stress response, but questions remain about how these organisms change their actual behaviors, like how they swim or develop, in response to these hormones. Burns and Genot are also interested in how other organisms in the ecosystem respond to these chemical shifts, and whether other algae species use these same hormonal cues for communication.

Beyond communication, though, the study also highlights the value of glaucophytes more broadly. Because of their unique place in the tree of life, how stable they are in the lab, as well as how fast they grow — Burns likens them to “weeds” — they’re a valuable tool for answering questions about evolutionary history and even developing algae-based products like plastic alternatives.

“The knowledge gap between what we know about these unicellular, photosynthetic eukaryotes and cultivated plants is still huge,” Genot said. “It’s challenging but exciting because we have so much more to learn about these little cells living all around us!”

 

Unlocking iron homeostasis: apple plants reveal key mechanism




NANJING AGRICULTURAL UNIVERSITY THE ACADEMY OF SCIENCE

A model of Fe homeostasis regulation by MdCML15–MdBT2–MdbHLH104–MdAHA8 in apple trees. 

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A MODEL OF FE HOMEOSTASIS REGULATION BY MDCML15–MDBT2–MDBHLH104–MDAHA8 IN APPLE TREES. WHEN APPLE ROOTS ARE EXPOSED TO FE-SUFFICIENT CONDITIONS, MDCML15 IS INDUCED TO INTERACT WITH MDBT2 IN THE NUCLEUS TO ACCELERATE MDBT2-MEDIATED UBIQUITINATION AND DEGRADATION OF MDBHLH104, RELIEVE TRANSCRIPTIONAL ACTIVATION OF MDAHA8, REDUCE H+ EFFLUX, AND THEREBY INHIBIT FE ABSORPTION AND PREVENT FE TOXICITY.

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CREDIT: HORTICULTURE RESEARCH



A pivotal study has uncovered the intricate dance between calcium signaling and iron regulation in apple plants. The research reveals how the calmodulin-like protein MdCML15 and the BTB domain protein MdBT2 interact to control iron homeostasis, offering new strategies for improving crop nutrition and yields. This discovery could transform agricultural practices by addressing the widespread issue of iron deficiency in crops, which significantly impacts both plant health and food production.

Iron is a vital micronutrient for plants, essential for photosynthesis, respiration, and various metabolic processes. Despite its abundance in the soil, iron often exists in insoluble forms, particularly in calcareous soils, making it difficult for plants to absorb. This limited availability can severely impact crop yields and plant health. Addressing these challenges requires a deeper understanding of iron uptake and regulation mechanisms in plants, which can lead to improved agricultural practices and the development of crops better suited to iron-deficient conditions.

Researchers from Nanjing Agricultural University have made significant strides in this field, with their findings (DOI: 10.1093/hr/uhae081) published in the Horticulture Research journal on March 25, 2024. The study explores the interaction between a calmodulin-like protein and an apple-specific BTB domain protein, key to iron homeostasis.

The study demonstrated that MdCML15 functions as an upstream regulator of MdBT2, which is involved in the ubiquitination and degradation of MdbHLH104. This process results in the reduced expression of MdAHA8, a plasma membrane H+-ATPase crucial for iron uptake. Consequently, the interaction between MdCML15 and MdBT2 negatively affects the plant's ability to acidify the rhizosphere and absorb iron. Transgenic apple plants overexpressing MdCML15 showed decreased iron uptake and severe chlorosis under iron-deficient conditions compared to wild-type plants. Conversely, plants with suppressed MdCML15 expression exhibited enhanced iron uptake and improved growth under the same conditions. These findings provide new insights into the regulatory network of iron absorption in apple trees and highlight the potential of targeting MdCML15 to improve iron uptake in crops.

Dr. Chun-Xiang You, one of the corresponding authors, stated, "Our findings highlight the intricate regulatory mechanisms plants use to balance nutrient uptake and avoid toxicity. Understanding the role of proteins like MdCML15 in these processes opens new avenues for developing crop varieties with improved nutrient efficiency."

This research provides valuable insights into the molecular mechanisms of iron regulation in apple trees. By manipulating the expression of MdCML15, it may be possible to enhance iron uptake in crops, leading to improved growth and yield, particularly in iron-deficient soils. This knowledge can inform breeding programs and biotechnological approaches aimed at developing nutrient-efficient crop varieties.

###

References

DOI

10.1093/hr/uhae081

Original Source URL

https://doi.org/10.1093/hr/uhae081

Funding information

This work was supported by grants from National Key Research and Development Program (2022YFD1201701), the National Natural Science Foundation of China (32001336 and 32272683), the China Agriculture Research System of MOF and MARA (CARS-27), and the Natural Science Foundation of Shandong Province (ZR2022QC093).

About Horticulture Research

Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2022. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.