Connect with us

Natural Sciences

Banana’s Large Plant Body Size an Advantage to Disease Control – Mak Scientists

Published

on

Unlike for plants, in animals especially humans, body mass index (BMI, which is a person’s weight divided by the square of height) is a measure of physical health and pre-disposure to conditions like obesity. BMI does not make sense in plant health because of differences between plant and animal physiological systems.

However, large body size in plants may have some advantages. Apart from controlling a larger proportion of available resources and space within crowded vegetation, what other advantage does a large plant body size offer to an individual plant?

Banana plant vegetative assembly.
Banana plant vegetative assembly.

The banana’s plant body architecture

From the botanical point-of-view, the banana plant is a gigantic herb. A plant that is a herb or “herbaceous” is unable to undergo “secondary growth” and cannot form wood during its vegetative development.

The banana plant springs from an underground “true stem”, also called the “corm” or “rhizome”, to form a false stem, also called a “pseudostem” of 2-7 m height. The pseudostem is composed of the basal portions of leaf sheaths and is crowned with a rosette of 10 to 20 oblong to elliptic leaves that sometimes attain a length of 2-4 m and a breadth of 70 cm.

Parts of the banana plant.
Parts of the banana plant.

In mature banana plants, true stem emerges at the top of the pseudostem and bends downward to become a bunch of 10 to 300 individual fruits, or fingers, grouped in clusters, or hands, of 3 to 22. The edible part of the bunch is the female. In contrast, the inedible distal part, including the purple-colored cone-shaped end (locally known in some Ugandan dialects as “omukanaana” or “empumumpu”) constitutes the male part of the bunch.

Longitudinal section of a banana corm (rhizome).
Longitudinal section of a banana corm (rhizome).

How is the giant banana size an advantage in disease control?

A new study, titled “Xanthomonas campestris pv. musacearum Bacterial Infection Induces Organ-Specific Callose and Hydrogen Peroxide Production in Banana” and led by a team of scientists at the Department of Plant Sciences, Microbiology and Biotechnology at Makerere University in collaboration with the University of California, Davis, USA, shows how the giant banana body size can be used to control banana Xanthomonas wilt (BXW) disease.

According to Prof. Arthur Tugume, the lead scientist of this study and expert in plant pathology, when plants get infected, they respond instantly by implementing different strategies that limit the multiplication and/or mobility of the disease agents (pathogens). “For example, plants rapidly produce reactive oxygen species (ROS) such as hydrogen peroxide, superoxide ions, and hydroxyl ions. These ROS act as rapid messengers in the plant tissues to activate additional responses spreading over the entire plant body. This helps the plant’s distant tissues or organs to be aware and prepare advance defenses against the intruding pathogens”.

An example of banana plantation in Uganda.
An example of banana plantation in Uganda.

Prof. Dinesh-Kumar the project’s research collaborator based at the University of California-Davis, USA and expert in plant biology explains that “disease is a form of stress in plants and plants cannot perform well their biological functions when they are sick since they have to spend a lot of energy fighting against the disease. This is why disease control is important to enable plants grow well and yield high.”

The research indicates that ROS set in motion additional processes to ensure limited impact of disease and pathogens on the plant. For example, Hydrogen peroxide (H2O2), which is a ROS, has direct bactericidal, fungicidal or other anti-effects on the pathogens. Also, following H2O2 production, a unique plant carbohydrate, named “callose” starts to accumulate in large quantities within plant cells as a means of fortifying plant tissues. Callose differs from the other usual plant carbohydrates such as starch or cellulose because of the way its structures are formed.

Some of the plantlets used in the experiments.
Some of the plantlets used in the experiments.

Increased production of callose acts as a roadblock to any pathogen e.g., bacteria by limiting bacterial movement that would otherwise allow ease of attack on other tissues or cells at distant locations in the plant. “Although these plant defense responses are rapid, plant organs that are distant from the site of pathogen attack can be instrumental and block progression of bacteria or other pathogens by depositing callose in advance at strategic points” Prof. Tugume explains.

However, Prof. Tugume notes that callose participates also in many other normal developmental processes of plants, and for that reason, there is always some “housekeeping” callose in the plant tissues even without pathogenic infection. “This means that one must be able to accurately and quantitatively distinguish between ‘stress-induced’ and normal ‘housekeeping’ callose”, he adds.

How was the study done?

In this study, the researchers used young (2.5-months old) banana plantlets that had been generated from tissue culture at Kawanda Agricultural Research Institute. They then infected the plantlets with a bacterium called Xanthomonas campestris pv. musacearum (Xcm). This bacterium is the causative agent of banana Xanthomonas Wilt (BXW), the most destructive disease of bananas in East and Central Africa (ECA).

The banana leaves, pseudostems, corms and roots were analyzed for callose and compared with the control plants that had been inoculated with water instead of bacteria. H2O2 production was monitored by “DAB staining”, and by “spectrophotometry” while the analysis of callose was done by two methods: staining and visualization of callose using florescence microscopy, and using “Sandwich Enzyme-Linked Immunosorbent Assay” methods.

A banana farmer removing a BXW infected plant from the mat. Only the infected plant is removed as a new method of BXW control.
A banana farmer removing a BXW infected plant from the mat. Only the infected plant is removed as a new method of BXW control.

What did the researchers discover and how can it be used in BXW disease control?

This study revealed that the underground corm tissues assemble the stiffest resistance against BXW by depositing the highest concentrations of callose, while the pseudostem produced the highest quantities of H2O2. This is interesting for three (3) main reasons:

  1. Firstly, Xcm bacteria often enter through the leaves in regular plantation husbandry; hence, the corm being distant from leaves gives it an anatomical advantage in promoting the ability of lateral plants to escape Xcm infection.
  2. Secondly, the corm is an organ of perennation supporting vegetative and perennial continuity of the crop across seasons; hence it is charged in ensuring a disease-free next generation by severely constraining “mother-child transmission” of Xcm bacteria.
  3. Thirdly, the control of BXW now becomes easy when farmers are observant to the first aerial disease symptoms because Xcm is strongly constrained by bottlenecks in the pseudostem and corm.

Therefore, at the onset of aerial symptoms, diseased peudostems should immediately be removed by aseptically cutting them off at the corm without interfering with symptomless lateral shoots, which allows continuous food production and disease control to go on simultaneously. This is facilitated by the large size of the banana plant because at the onset of leaf symptoms (2.5 to 5 meters away from the corm), the bacteria have not yet arrived at the base of the pseudostem where the diseased plant can be cut off from the corm. This gives chance to a farmer to eliminate the infected pseudostems early (in 1 to 7 days) since the appearance of leaf symptoms.

This research was part of the PhD studies for Mr. Abubakar S. Mustafa at Makerere University and University of California, Davis. According to Mr. Mustafa, these discoveries make the management of BXW in banana plantations easy as long as the farmers are observant and act fast by removing diseased plants aseptically.

This study has been published by the American Phytopathological Society (APS) in an open access journal, “PhytoFrontiers”, and is freely accessible on https://apsjournals.apsnet.org/doi/full/10.1094/PHYTOFR-11-21-0073-R.

This study was funded by the Bill and Melinda Gates Foundation through the National Agricultural Research Organization (NARO), Uganda. The project had partners including the International Institute of Tropical Agriculture (IITA), the Alliance for Bioversity International and International Centre for Tropical Agriculture (CIAT) and Centre for Agriculture and Bioscience International (CABI).

For more details, contact;

Prof. Arthur Tugume
Lead Scientist
College of Natural Sciences (CoNAS)
Makerere University
Email: arthur.tugume@mak.ac.ug
Tel: +256772514841

Mr. Abubakar S. Mustafa
Co-Author and PhD student on the study
Email: mustafa.abubakar.sadik@gmail.com
Tel: +256702813233

Hasifa Kabejja
Principal Communication Officer
College of Natural Sciences (CoNAS)
Makerere University
Email: pr.cns@mak.ac.ug
Tel: +256774904211

Natural Sciences

Call For Applications For Masters Scholarship Under The Biosorption For Sustainable Small-Scale Gold Mining In Uganda (BioGold) Project

Published

on

The JICA Building, College of Natural Sciences (CoNAS) as approached from the Mary Stuart Road Roundabout, Makerere University, Kampala Uganda

BioGold Project is a three-year collaborative project among five academic institutions including, Kyambogo University, Makerere University, Gulu University, University of Pretoria and University of Continuing Education, Krems, Austria funded by the Austrian Development Cooperation under the APPEAR Partnership. The project will combine principles of biosorption and chemical remediation to treat contaminated wastewater, tailings, rehabilitate contaminated soils so as to protect vulnerable ecosystems surrounding artisanal gold mining (ASGM) areas in Uganda. This study will design biochar composites from locally available biomass to enhance mercury removal from wastewater and tailings as well as rehabilitate mercury-contaminated soils making them fit for agriculture. The project envisages to train and build capacity of young researchers in Uganda. As such the project has been allocated an MSc. position under Component II, to support to full-time student to undertake studies in Austria. The successful MSc candidate is expected to undertake research on characterizing, optimizing biochar and modify the biochar to improve the sorption capacities.

The project consortium is now inviting qualified and interested persons to apply for nomination for the award of the scholarship. The project has strong preference for female candidates, therefore strongly encouraged to apply.

Eligibility criteria

In addition to APPEAR requirements https://appear.at/en/implementation/embedded-scholarship-application, the applicants should:

  1. Not be older than 30 years (women not older than 35)
  2. Demonstrate interest and capability to work in the priority themes
  3. Present a concept note to provide understanding of the subject
  4. Have a minimum of second- upper class bachelor’s degree in any of the following programmes: BSc in Chemistry, BSc in Environmental Science, & BSc in Environmental Engineering

Benefits

The successful applicants will receive a full scholarship (up to 24 months) which includes;

  1. Return air ticket and visa costs to Austria
  2. Monthly stipend of €1000 while in Austria to cater for personal welfare, accommodation and local movement
  3. Research related expenses.

Application process

  1. A complete application form
  2. A one-page motivation letter
  3. Curriculum vitae (maximum 2 pages)
  4. A completed Master Scholarship Application Form for Embedded APPEAR Projects
  5. Copies of Academic documents
  6. Photocopy of the passport and/or ID
  7. Recommendation letters from two academic referees.
  8. All applications must be sent electronically to Dr. Mary Kaggwa (marykaggwa@kyu.ac.ug) and copied to Dr. Peter Akoll (peter.akoll@mak.ac.ug) and Dr. Denis Nono (d.nono@gu.ac.ug) not later than 5.00pm East African Time on 20th June 2024.

Members of staff with former students interested in biochar technology and its use in heavy metal removal are requested to share the advert with them.

Full Advert and Application form may be accessed below.

Note: Only successful applicants will be contacted.

View on CoNAS

Continue Reading

Natural Sciences

Mak Researchers Set Out to Address the Challenge of African swine fever in Uganda

Published

on

Professor Charles Masembe, CoNAS, Makerere University. Image:ASF

The Project is supported by the Government of Uganda through the Makerere University Research and Innovations Fund (Mak-RIF).

Overview

African swine fever (ASF) is a highly contagious viral haemorrhagic disease of domestic pigs; and has recently spread to new areas including Eastern Europe and in Asia as far as Papua New Guinea. This disease has neither vaccine nor treatment and is currently a big challenge to many smallholder pig farmers in Uganda. In Uganda, ASFV genotype IX has been reported to cause outbreaks on a regular basis and is an impediment to development of the swine industry. The disease was previously reported with a mortality of 100%. However different forms of the disease have recently been observed in domestic pigs. Indeed, some studies have shown that pigs that survive ASF become resistant to the same viral isolates although they do not produce classical neutralizing antibody. These observations could have the key for vaccine development strategies.

The Principal Investigator of ASF-RESIST, Dr. Charles Masembe; an Associate Professor in the Department of Zoology, Entomology and Fisheries Sciences (ZEFS), CoNAS, Makerere University, Kampala Uganda
The Project Principal Investigator (PI), Prof. Charles Masembe.

The research project

Through a project titled “African swine fever virus (ASFV) severity and viral genomic structural features: opportunities for development of a vaccine in Uganda”, a team of researchers led by Prof. Charles Masembe from the Department of Zoology, Entomology, and Fisheries Sciences at Makerere University registered the need to correlate clinical studies of ASF virus with full genome sequences and virus structural data to identify potential candidate genes for vaccine development. The team set out to isolate and characterise highly virulent and low virulent ASF viruses circulating in the swine population in Uganda using next-generation and Electron Microscopy to inform the development of ASFV vaccines and other therapeutic strategies. The team also set out to sequence the whole genome of low and high-virulence African swine fever viruses circulating in the domestic pig population in Uganda; compare the whole genome sequences of low and high-virulence ASF viruses in Uganda, and to find genomic variations and their effects on the virulence and viral evolution. Whole blood and organ tissue samples together with clinical-epidemiological information, were collected from acute and chronic cases of pigs in reported ASF outbreaks in the districts of greater Masaka, Greater Gulu, Mukono, Wakiso, Kakumiro, and additionally in other districts were outbreaks were reported during the study period. The project was supported by the Government of Uganda through the Makerere Research and Innovations Fund (MakRIF). Other members on the project are; Assoc. Prof. Vincent Muwanika (Co-PI), Dr. Rose Ademun (Scientist), Dr. Mathias Afayoa (Scientist), Dr. Tony Aliro (Field Scientist), Mr. Peter Ogweng (Field Scientist),  Mr. Mayega Johnson Francis (Lab Technologist), Okwasiimire Rodney (Lab Technologist), and Mr. Bright Twesigye (Administrator).

The Project team at the research dissemination workshop in Gulu District. Prof. Charles Masembe, Department of Zoology, Entomology, and Fisheries Sciences, College of Natural Sciences (CoNAS), Makerere University Research and Innovations Fund (Mak-RIF)-funded "African swine fever virus (ASFV) severity and viral genomic structural features: opportunities for development of a vaccine in Uganda” project research dissemination, 15th May 2024, Doves Nest Hotel, Gulu District, Northern Uganda, East Africa.
The Project team at the research dissemination workshop in Gulu District.

Dissemination of the research findings

On 15th May 2024, the project team held a workshop at Doves Nest Hotel in Gulu District to disseminate the research findings, and to fact check by mapping pig farms, abattoirs, slaughter slabs, and pork restaurants in both Gulu District and Gulu City for on-going and future research.

The workshop was officially opened by the Assistant Chief Administrative Officer (CAO) of Gulu District, Mr. Okidi Cosmas James on behalf of the CAO. In his remarks, Mr. Okidi appreciated the project team, noting that the workshop was timely since piggery as a poverty alleviation programme had been embraced by most farmers as a replacement for cattle. Sharing his experience, he expressed concern over the increasing threat of ASF, a factor he said was undermining the growth of the swine industry in Uganda.

Prof. Masembe interacts with the participants during the workshop. Prof. Charles Masembe, Department of Zoology, Entomology, and Fisheries Sciences, College of Natural Sciences (CoNAS), Makerere University Research and Innovations Fund (Mak-RIF)-funded "African swine fever virus (ASFV) severity and viral genomic structural features: opportunities for development of a vaccine in Uganda” project research dissemination, 15th May 2024, Doves Nest Hotel, Gulu District, Northern Uganda, East Africa.
Prof. Masembe interacts with the participants during the workshop.

During the meeting, the Project PI, Prof. Charles Masembe presented the status of ASF research in Uganda and globally, highlighting the complexity of ASF, dangers of ASF, ASF diagnostic advances, importance of keeping pigs and scientific efforts to control ASF, including the advances in the development of the ASFV vaccine. 

Other presentations focused on ASF control and prevention mechanisms, potential role of production systems in ASF transmission, community involvement in disease control, spatio-temporal spread of ASF at the wildlife-livestock interface, the role of carrier pigs in ASFV transmission and maintenance, biosecurity implementation and challenges. All these presentations evoked discussion points from the participants. Participants expressed the need to understand how ASF is transmitted, and the extent to which farmers can trust veterinarians since they are considered to spread the disease. They highlighted the need to institute quarantine during ASF outbreaks and called for sensitization on the acceptable methods for disposing off infected pork. Another concern arising from the meeting was the need to understand if ASF is zoonotic and if not, why ASFV infected pork should not be eaten. Participants also sought guidance on why farmers should continue to keep survivor pigs if they spread ASFV, and why the government has not constructed slaughter slabs in all villages to control the spread of ASFV.

Participants in an exercise to map out pig farms/farmers, abattoir/slaughter slabs and pork restaurants in their respective sub counties to support the research process. Prof. Charles Masembe, Department of Zoology, Entomology, and Fisheries Sciences, College of Natural Sciences (CoNAS), Makerere University Research and Innovations Fund (Mak-RIF)-funded "African swine fever virus (ASFV) severity and viral genomic structural features: opportunities for development of a vaccine in Uganda” project research dissemination, 15th May 2024, Doves Nest Hotel, Gulu District, Northern Uganda, East Africa.
Participants in an exercise to map out pig farms/farmers, abattoir/slaughter slabs and pork restaurants in their respective sub counties to support the research process.

Recommendations by participants;

  1. Strengthening community awareness through different production departments in the district and city by organizing workshops as closer to the farmers as possible for example at every parish or ward.
  2. Makerere University ASF research team should collaborate with Gulu University, Faculty of Agriculture and Environmental Studies so that ASFV diagnosis and research is jointly done at the University which is nearer to the farmers for quick response to ASF outbreaks.
  3. City, District, and sub-county leaders should formulate a by-law to enforce the implementation of ASF control and prevention methods.
Mapping pig farms/farmers, abattoir/slaughter slabs and pork restaurants. Prof. Charles Masembe, Department of Zoology, Entomology, and Fisheries Sciences, College of Natural Sciences (CoNAS), Makerere University Research and Innovations Fund (Mak-RIF)-funded "African swine fever virus (ASFV) severity and viral genomic structural features: opportunities for development of a vaccine in Uganda” project research dissemination, 15th May 2024, Doves Nest Hotel, Gulu District, Northern Uganda, East Africa.
Mapping pig farms/farmers, abattoir/slaughter slabs and pork restaurants.

During plenary, participants were tasked with mapping pig farms/farmers, abattoir/slaughter slabs and pork restaurants in their respective sub-counties in Gulu District and Gulu City, in addition to generating a comprehensive farm/farmer list in the two areas. Mapping was successfully done and presented for purposes of clarity by each team representing a particular sub-county. The participants were then given a template to populate on the farm/farmer list since they could not recall all farms/farmers name and their mobile phone contacts.

Participants pose for a group photo. Prof. Charles Masembe, Department of Zoology, Entomology, and Fisheries Sciences, College of Natural Sciences (CoNAS), Makerere University Research and Innovations Fund (Mak-RIF)-funded "African swine fever virus (ASFV) severity and viral genomic structural features: opportunities for development of a vaccine in Uganda” project research dissemination, 15th May 2024, Doves Nest Hotel, Gulu District, Northern Uganda, East Africa.
Participants pose for a group photo.

Remarks by Gulu District RDC

In his closing remarks, the RDC of Gulu District, Mr. Oryem Auric thanked the research team for choosing the district for the workshop, noting that the feedback from the participants indicated that the workshop was very beneficial to them. He pledged to dedicate some of the free airtime offered to his office on Radio Mega, a popular FM Radio Station in Gulu City affiliated to Radio Uganda, towards the popularization of the project activities. He reiterated that the objectives of the project were in line with the current Government of Uganda programme on wealth creation through the Parish Development Model and the 4 acre model of which piggery is one of the means recommended for poverty alleviation by the President of Uganda. He called on the farmers to embrace and utilize the knowledge acquired to improve their farms and increase their household incomes.

View on CoNAS

Continue Reading

Natural Sciences

CoNAS Annual Report 2023

Published

on

Cover page of the CoNAS Annual Report 2023. College of Natural Sciences, Makerere University, Kampala Uganda, East Africa.

The College of Natural Sciences (CoNAS) is one of the 10 constituent Colleges of Makerere University with over 2,000 students and 153 members of staff spread across 2 schools and seven departments namely: School of Physical Sciences (Physics, Chemistry, Mathematics, Geology and Petroleum Studies) and School Biosciences (Departments of Plant Sciences, Microbiology and Biotechnology; Department of Zoology, Entomology and Fisheries Sciences; and Department of Biochemistry and Sports Sciences). The College is the cradle of basic sciences at Makerere providing a foundation for all applied sciences offered at the University. This report is a presentation of the performance of the College in 2023.

Key highlights include performance of the College at the 74th graduation of Makerere University, the award of an Honorary Doctor of Science to Prof. Leif Abrahamsson for his contribution to the development of Mathematics in the East African region, the development of an E-Supervision Web Portal (https:/mastersresearch.ug/) to support the tracking of Masters Research supervision processes, the formation and operationalization of the Biology Society of Uganda (BioSU), support rendered towards the development of aquaculture in the country, the development of five high-value nutritious products (baby food, sauce, maize meal, snacks, and seasoning) using Mukene through the NutriFish Project, the development of an application for tracking fish catches as a measure to prevent overfishing, development of solar tent driers – greenhouse-like structures that reduce the risk of contamination – provide clean and efficient storage and drying, especially during the wet season subsequently reducing post-harvest losses, equipping students and members of the general public with skills needed in the installation and maintenance of solar energy Photovoltaic systems and biogas plants, the Joint African- Nordic Conference in Mathematics, as well as the 2023 Eastern Africa Algebra Research Group and Women in Sage workshops. The report also highlights the research grants received in the course of the year, conferences held, community engagements, activities by students, awards received by the different members of staff, staff publications, and matters of Human Resources at the College.

Management conveys appreciation to all development partners and the Government of Uganda for the support extended towards the different projects at the College. We also thank the University Council and Management for creating a conducive environment for both staff and students to explore their full potential.

Continue Reading

Trending