Steven Lee Stephenson

Dr. Steven Lee Stephenson

orcid

Research Focus & Metrics

Academic Career Length

45Years (1982-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
28 July 2024 in New Zealand Journal of Botany
Verified
Journal Article
Closed access
ARAchala Rathnayaka
Achala Rathnayaka
Danushka Sandaruwan TennakoonDanushka Sandaruwan Tennakoon
Danushka Sandaruwan Tennakoon
GJGareth E.B. Evan Benjamin Jones
Gareth E.B. Evan Benjamin Jones
Dhanushka Nadeeshan WanasingheDhanushka Nadeeshan Wanasinghe
Dhanushka Nadeeshan Wanasinghe
DBD. Jayarama Bhat
D. Jayarama Bhat
Samantha C. KarunarathnaSamantha C. Karunarathna
Samantha C. Karunarathna

25 July 2022 in Journal of Fungi
Verified
Journal Article
Open access
PDF file
AEAnusha Ekanayaka
Anusha Ekanayaka
Saowaluck TibprommaSaowaluck Tibpromma
Saowaluck Tibpromma
DDDong-Qin Dai
Dong-Qin Dai
RXRuifang Xu
Ruifang Xu
Nakarin SuwannarachNakarin Suwannarach
Nakarin Suwannarach
Samantha C. KarunarathnaSamantha C. Karunarathna
Samantha C. Karunarathna
Plastic has become established over the world as an essential basic need for our daily life. Current global plastic production exceeds 300 million tons annually. Plastics have many characteristics such as low production costs, inertness, relatively low weight, and durability. The primary disadvantage of plastics is their extremely slow natural degradation. The latter results in an accumulation of plastic waste in nature. The amount of plastic waste as of 2015 was 6300 million tons worldwide, and 79% of this was placed in landfills or left in the natural environment. Moreover, recent estimates report that 12,000 million tons of plastic waste will have been accumulated on the earth by 2050. Therefore, it is necessary to develop an effective plastic biodegradation process to accelerate the natural degradation rate of plastics. More than 400 microbes have been identified as capable of plastic degradation. This is the first paper of the series on plastic-degrading fungi. This paper provides a summary of the current global production of plastic and plastic waste accumulation in nature. A list is given of all the plastic-degrading fungi recorded thus far, based on the available literature, and comments are made relating to the major fungal groups. In addition, the phylogenetic relationships of plastic-degrading fungi were analyzed using a combined ITS, LSU, SSU, TEF, RPB1, and RPB2 dataset consisting of 395 strains. Our results confirm that plastic-degrading fungi are found in eleven classes in the fungal phyla Ascomycota (Dothideomycetes, Eurotiomycetes, Leotiomycetes, Saccharomycetes, and Sordariomycetes), Basidiomycota (Agaricomycetes, Microbotryomycetes, Tremellomycetes, Tritirachiomycetes, and Ustilaginomy-cetes), and Mucoromycota (Mucoromycetes). The taxonomic placement of plastic-degrading fungal taxa is briefly discussed. The Eurotiomycetes include the largest number of plastic degraders in the kingdom Fungi. The results presented herein are expected to influence the direction of future research on similar topics in order to find effective plastic-degrading fungi that can eliminate plastic wastes. The next publication of the series on plastic-degrading fungi will be focused on major metabolites, degradation pathways, and enzyme production in plastic degradation by fungi.

27 September 2022 in Sustainability
Verified
Journal Article
Open access
PDF file
RKRuwanthika Kalamulla
Ruwanthika Kalamulla
SKSamantha C. Karunarathna
Samantha C. Karunarathna
Saowaluck TibprommaSaowaluck Tibpromma
Saowaluck Tibpromma
Mahesh Chathuranga Abraham GalappaththiMahesh Chathuranga Abraham Galappaththi
Mahesh Chathuranga Abraham Galappaththi
Nakarin SuwannarachNakarin Suwannarach
Nakarin Suwannarach
NYNeelamanie Yapa
Neelamanie Yapa
The coevolution of mycorrhizae with plants represents a major evolutionary adaptation to the land environment. As a bioinoculant, arbuscular mycorrhizal fungi (AMF) play a beneficial role in sustainable agriculture by symbiotically associating with many crop plants. In this review, we primarily focus on the nutritional and non-nutritional functionality of AMF in soil and plant productivity. AMF maintain soil quality and health via three aspects: soil structure, plant physiology, and ecological interactions. These lead plants to increase their functionality, further growth, and productivity. The formation of soil aggregates via glomalin production maintains the soil structure. Physiologically, AMF change nutrient acquisition and thereby increase soil fertility and productivity. Biotic (pathogens and weed plants) and abiotic (salinity, drought, extreme temperature, soil pH, and heavy metals) stress alleviation is also achieved via altering a plant’s physiological status. By serving as a biocontrol agent, AMF negatively interact with plant pathogens. As a result of beneficial interactions with other rhizosphere microorganisms and above-ground organisms, AMF induce a synergistic effect on plant performance. Moreover, they are also involved in land restoration and seedling establishment. The collective effect of all these functions positively influences overall plant performance and productivity.

21 July 2011 in Fungal Diversity
Verified
Journal Article
Closed access
PDF file
SSSteven Lee Stephenson
Steven Lee Stephenson
Myxomycetes (plasmodial slime molds or myxogastrids) are a group of eukaryotic microorganisms usually present and sometimes abundant in terrestrial ecosystems. Because they produce aerial spore-bearing structures that resemble those of certain fungi and also typically occur in some of the same types of ecological situations as fungi, myxomycetes have been traditionally studied by mycologists, and this continued to be the case for the greater part of the twentieth century. However, there is now abundant molecular data to confirm that they are amoebozoans and not fungi. Efforts are currently underway to develop the first molecular phylogeny for myxomycetes, and several recent studies have used molecular techniques to detect the presence of these organisms in nature by means of direct environmental sampling.

2 June 2023 in Biology
Verified
Journal Article
Open access
PDF file
A.K Hasith PriyashanthaA.K Hasith Priyashantha
A.K Hasith Priyashantha
DDDong-Qin Dai
Dong-Qin Dai
DBDarbhe J. Bhat
Darbhe J. Bhat
SSSteven Lee Stephenson
Steven Lee Stephenson
IPItthayakorn Promputtha
Itthayakorn Promputtha
Samantha C. KarunarathnaSamantha C. Karunarathna
Samantha C. Karunarathna
Fungi live different lifestyles—including pathogenic and symbiotic—by interacting with living plants. Recently, there has been a substantial increase in the study of phytopathogenic fungi and their interactions with plants. Symbiotic relationships with plants appear to be lagging behind, although progressive. Phytopathogenic fungi cause diseases in plants and put pressure on survival. Plants fight back against such pathogens through complicated self-defense mechanisms. However, phytopathogenic fungi develop virulent responses to overcome plant defense reactions, thus continuing their deteriorative impacts. Symbiotic relationships positively influence both plants and fungi. More interestingly, they also help plants protect themselves from pathogens. In light of the nonstop discovery of novel fungi and their strains, it is imperative to pay more attention to plant–fungi interactions. Both plants and fungi are responsive to environmental changes, therefore construction of their interaction effects has emerged as a new field of study. In this review, we first attempt to highlight the evolutionary aspect of plant–fungi interactions, then the mechanism of plants to avoid the negative impact of pathogenic fungi, and fungal strategies to overcome the plant defensive responses once they have been invaded, and finally the changes of such interactions under the different environmental conditions.

21 October 2022 in Journal of Fungi
Verified
Journal Article
Open access
PDF file
li LUli LU
li LU
Samantha C. KarunarathnaSamantha C. Karunarathna
Samantha C. Karunarathna
DDDong-Qin Dai
Dong-Qin Dai
YXYin-Ru Xiong
Yin-Ru Xiong
Nakarin SuwannarachNakarin Suwannarach
Nakarin Suwannarach
Saowaluck TibprommaSaowaluck Tibpromma
Saowaluck Tibpromma
In Yunnan Province, the coffee-growing regions are mainly distributed in Pu’er and Xishuangbanna. During the surveys of microfungi associated with coffee in Yunnan Province, seven taxa were isolated from coffee samples. Based on molecular phylogenetic analyses of combined ITS, LSU, SSU, rpb2, and tef1-α sequence data and morphological characteristics, four new species viz. Deniquelata yunnanensis, Paraconiothyrium yunnanensis, Pseudocoleophoma puerensis, and Pse. yunnanensis, and three new records viz. Austropleospora keteleeriae, Montagnula thailandica, and Xenocamarosporium acaciae in Pleosporales are introduced. In addition, Paracamarosporium fungicola was transferred back to Paraconiothyrium based on taxonomy and DNA sequences. Full descriptions, illustrations, and phylogenetic trees to show the placement of new and known taxa are provided. In addition, the morphological comparisons of new taxa with closely related taxa are given.