Abstract

Melanins are complex polymers that are synthesized by members of all biological kingdoms, making them one of the great natural pigments. Despite the abundance of melanins in our planet's biomass, there remains a great deal of mystery surrounding this pigment. Fungi produce and utilize melanins in the enviroment and during disease conditions. Ongoing studies have revealed remarkable structural characteristics of this enigmatic pigment and have uncovered intreguing associations of melanin to fungal virulence. In this session, we will review what we know about fungal melanin and were this knowledge is taking us.

Abstract

Understanding the molecular basis for survival in stress tolerant species goes hand in hand with the search for metabolites, compounds, and macromolecules playing a role in mechanisms of adaptation and being, at the same time, of possible biotechnological interest. The constant search for new products by the industry has indeed shifted the attention to extremophilic and extremotolerant organisms as potential producers of compounds with novel and unusual characteristics and functional activities under life-threatening conditions.

Reflecting this tendency, the objective of the present study is to deepen the knowledge on ecophysiology and systems biology of black fungi – a group of ascomycetes considered as among the most resistant Eukaryotes know to date – as well as to detect species possessing polymer degradation ability. Hence, the extremotolerant rock-associated species Knufia chersonesos and its nonmelanized spontaneous mutant, whose degradation skills have been revealed by preliminary studies, were chosen for a proteomic-based screening towards polyesterases.

Induced cultures – characterized by the addition of the biodegradable polyester poly(1,4-butylene adipate-coterephthalate) (PBAT) to the growth media – and control cultures were analysed by HPLC to determine the polymer hydrolysis. Both whole PBAT film and milled were tested. The induction was performed both in rich (2% malt extract, ME) and minimal medium (0.2% ME) aiming to test K. chersonesos ability to use PBAT as its sole carbon source. HPLC/MS identification and quantitation of the hydrolysis products terephtalic acid (Ta), mono(4-hydroxybutyl) terephthalate (BTa) and bis(4-hydroxybutyl) terephthalate (BTaB) indicated the presence of esters-hydrolyzing enzymes in the secretome of both strains and under induction with both whole and milled PBAT film. Ta was detected as the most abundant hydrolysis product, thus denoting degradation of PBAT to the smallest building block, especially in culture supernatants from minimal medium, resulting in up to 2-fold higher concentrations as compared to the other experimental conditions. Polymer hydrolysis was detected also when exposing un-induced growth media to the polymer, up to 70°C . Label-free shotgun proteomics and protein profiling showed largest differences in secretome composition and protein levels between minimal and reach growth medium. While at the optimal condition of growth an abundant and diverse set of proteins was detected growth on minimal medium lead to secretion of mostly carboxylic esterases.

Our results on the extracellular proteome of K. chersonesos demonstrate that the culture supernatant has hydrolytic ability when grown in standard media and when PBAT is added to the media. In conclusion, these analyses of polyester degrading activity show that the proteomic screenings of an organism’s extracellular proteome can aid the identification of novel polyesterases.

Abstract

Paracoccidioidomycosis (PCM) is a granulomatous systemic mycosis, whose etiological agents are dimorphic fungi of the genus Paracoccidioides. Melanin production by various fungi interferes in the mechanism of pathogenesis, and the same is observed in paracoccidioidomycosis. After analysis of melanin production by P. lutzii isolates (Pb01,Pb66, ED01,Pb1578and Pb8334) and P. brasiliensis isolates (Pb60855, Pb18 and Pbcão), we verified the ability of macrophages to phagocytose the highly virulent isolate Pb18, and the high and low producers of melanin isolates, Pb60855 and Pb01, respectively. Phagocytosis assay was carried out with C57BL/6 mice peritoneal macrophages that were challenged with antibodies/complement-treated or untreated yeast cells. Results showed that the presence of high concentrations of melanin reduced significantly the percentage of phagocytosed untreated Pb60855 and Pb18 yeast cells when compared to Pb01 isolate. SDS-PAGE protein and enzymatic profiles, including laccase activity, of the isolates Pb18, Pb60855 and Pb01 were also analyzed. The isolated Pb01 produced fewer proteins than Pb18 and Pb60855 in the tested conditions, as well as the laccase enzyme activity was reduced in isolate Pb01. Molecular phylogenetic studies have indicated two distinct clades among the genus Paracoccidioides: the lutzii clade containing P. lutzii species and the brasiliensis clade that harbors five phylogenetic cryptic species (S1a, S1b, PS2, PS3, and PS4) that were recently reclassified as formal species: P. americana (PS2), P. restrepiensis (PS3), P. venezuelensis (PS4) and P. brasiliensis sensu strictu (S1a and S1b). Our study included a representative isolates from each new formal species, that gives a differential production of melanin, lacasse, proteins and enzymatic profiles that could be explain the virulence among them. We conclude that the presence of lower concentrations of melanin and the reduced production of protein/enzymes by P. lutzii Pb01 isolate can be related to the augmented phagocytosis of these yeast cells by macrophages in vitro, explaining the reduced virulence of this isolate in vivo, in front of the other spices. Suggesting that there may be a differential expression of the virulence factors according to species that should be better studied.

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Increased awareness of systematic biases across the Sciences, Technology, Engineering and Mathematics (STEM) has fueled calls for action across scientific disciplines. In a recent analysis of gender equality within the Mycological Society of America (MSA), Branco and Vellinga found evidence of gender bias, both in serving officers and awards. At the time of the Branco and Vellinga report, there was no information on other aspects of diversity (e.g. race, age, professional status) within the MSA, as membership demographic information had never before been collected. Following the publication of this report, the MSA created a Diversity and Inclusion Committee with the goal of identifying and implementing specific actions to counteract potential biases pertaining to diversity within the society. The committee is made up of male and female MSA members, international, and Lesbian/Gay/Bi/Trans/Questioning (LGBTQ) mycologists from across academic rank, including graduate students, postdocs, and faculty. To better understand the demographic make-up of MSA the first membership assessment was conducted in 2016. In an anonymous online survey, MSA members were asked to provide responses to questions in the following categories: gender, age group, professional status, race, ethnicity, citizenship, sexual orientation, disability, family status, and annual income. Each question included a ‘choose not to answer’ option so members were free to answer (or not answer) any number of questions. Fillable text boxes were also included so members could generate their own responses or elaborate on their response to each question. The response to the survey was positive, with over 330 MSA members participating. Results show areas of relative high diversity within the MSA (e.g. international membership, LGTBQ members) but also highlight areas that could be improved. For instance, although gender ratios tended to be fairly balanced among students, gender bias became more pronounced in the more academically advanced categories. The survey also revealed that although MSA is made up of members from at least 15 different countries, there is low racial diversity within the society, reflecting known trends in the STEM fields. Because only specific actions to counteract diversity biases can make MSA more inclusive, the MSA Diversity and Inclusion Committee developed a set of best practices to be incorporated into the MSA Manual of Operations. For example, when MSA committees are identifying potential speakers to invite for annual meetings, best practices suggest that committees should strive for balance among disciplines, and diversity in gender, race, and ethnicity. An emphasis on providing professional development opportunities to a wide diversity of scientists could be critical for the long-term sustainability of the society. MSA members who are successful professionally will be more likely to maintain active membership, and moving forward, could help to improve recruitment and retention of a diversity of students and professionals within the society.

Abstract

The scientific method is an organized process for experimentation, used to explore observations and answer questions about the natural world. This method of inquiry aims to be as objective as possible, but the humans conducting research are not themselves immune to bias. Both within scientific culture and beyond, stereotypes about what a ‘typical’ scientist looks like can result in unconscious bias. Unconscious bias, also called implicit bias, is defined as prejudice in favor of or against one thing, person, or group compared with another, usually in a way considered to be unfair. Unconscious bias has been to reduce bias and its effects.In this talk, I will briefly discuss how stereotypes harm people and impact productivity, and then explain how exposure to stereotypes results in unconscious bias. I will share a number of peer-reviewed studies documenting how different types of unconscious bias impacts diversity, equity and inclusion in STEM. I will then provide evidence-based techniques to reduce unconscious bias and limit its effects. I will conclude with a few approaches for mycologists to reduce unconscious bias in themselves and guidance on how best to intervene when others speak or act with bias.

Abstract

Strong gender and racial biases in STEM fields are prevalent and well documented. Underrepresented groups face implicit and explicit hurdles in career progression, hampering access to positions of power, and leading to lower wages and low retention rates. As data for such biases in Mycology were virtually inexistent, we investigated gender balance in the Mycological Society of America (MSA) by compiling numbers on membership, officers and awards. We found male dominance in membership, officer positions (with 30% female presidents in the last 20 years), and non-student awards (including the most prestigious MSA award, granted to 55 male and 5 female mycologists). Notably, gender was near balanced in student membership and student awards. These results catalyzed the creation of the Diversity and Inclusion Committee, aiming at fostering diverse and inclusive participation in all MSA activities. This active and diverse committee compiles data on the composition of MSA membership, provides recommendations for an equitable and inclusive environment in the society and conducts outreach to foster participation of all MSA members.

Abstract

Diversity is a multidimensional concept that, among other aspects, entails age, religion, race, ethnicity, gender and gender identity, and work experiences. Even though this concept is not new, academic and non-academic research institutions have relatively recently implemented policies to assure diversity is reflected in their hiring processes, promoting the recruitment of professionals with diverse backgrounds. In this way, research organizations are acknowledging that diversity contributes to the richness of the environment for teaching and research. Bringing more diversity into science creates a wider variety of views and experiences that can greatly benefit research and education. Even with these efforts put in place, the agricultural sciences, which includes mycology and plant pathology, is still considered a male dominated field with positions traditionally filled by scientists with very specific-and usually applied- research experience. Fortunately, as more institutions recognize the value of diversity, changes are happening and scientists with diverse social, cultural, and intellectual backgrounds are having more opportunities of employment. As a Latin American mycologist, the journey to a stable position has not been easy. I obtained my graduate degrees from American institutions, but conducted most of my research in tropical countries. Moreover, I had dedicated most of my research to answer “basic research” questions. Due to the current low funding rates, experienced by most scientific communities, accessing to resources and/or stable research positions has become a challenge and a source of frustration for many early career researchers. In this talk, I would like to discuss the topic of diversifying our job search approaches and exploring opportunities within applied agricultural fields. In particular, I would like to share my recent experiences running a small plant diagnostic clinic and developing an integrated research and extension program at a land-grant university affiliated research and education center. Plant diagnostics can be a very rewarding and creative career path with direct positive impacts on the community we live in and on the livelihood of its inhabitants. Agriculture is still the dominant economic activity and income source in many regions, even in developed nations, thus working on solving problems directly associated to this industry makes these jobs relevant and on high demand.

Abstract

Of the approximate 361.1 million people living in the US, 3.5% identify as part of the LGBT spectrum. Of the 332 MSA members who participated in our 2016 Diversity Survey, 43% identify as female, 56% as male, and 1% as trans. Of those surveyed, 11% identify as LGBTQ. The question is whether we are doing enough to welcome those who identify as LGBT+ within the STEM fields, more specifically, mycology – which are still dominated by cisgender persons. There are many terms to describe persons who identify themselves as other than heterosexual or gender conforming. One umbrella-term is LGBTQQIAAP, which stands for lesbian, gay, bisexual, transgender, queer, questioning, intersex, asexual, allies, pansexual, or polysexual. Here we choose to use LGBT+. Gender identity and sexuality should not matter in the sciences, where instead we should focus on formulating research questions, designing experiments, collecting and analyzing data, publishing results and training students. But they still do. To gain more understanding of current trends on LGBT+ in STEM, an online survey was initiated in 2018 and circulated by membership email, on email listservs and through social media networks. The following questions were posed: Do you feel that you can be open about your sexual orientation and/or gender identity in your academic department or professional workplace? Did or will your being LGBT+, or your gender identity, affect your career decisions? Have you had negative reactions from colleagues about your being LGBT+ or because of your gender identity? Have you ever felt that your being LGBT+ or your gender identity has played a role in missing out on academic or outreach opportunities, assignments, or chances to move forward in your career? Have you had any positive reactions from colleagues about your being LGBT+ or because of your gender identity? Have you ever observed harassment in your work environment dealing with someone else's sexual orientation or gender identity? Do you have STEM role models who are open about being LGBT+ or their gender identity? Have there been times when being LGBT+, or gender non-conforming, felt isolating in your career, academic department, or professional societies? Would you appreciate an LGBT+ social event and/or mentoring session at conferences to promote networking? Would you appreciate a spokesperson within academic conferences to assist with being out and building a professional career as LGBT+? Participants answered yes or no and were requested to elaborate on their answers. A final question was added: How do you feel in your work environment? In their answer, participants selected one of five options from “very comfortable” to “very uncomfortable,” and again were requested to elaborate. Altogether, this work will reveal the challenges and perspectives of the LGBT+ in STEM and will provide insights on potential efforts and opportunities that the science community can adopt to create a more inclusive STEM environment, particularly within the MSA.

Abstract

Rice blast, caused by Magnaporthe oryzae, is one of the most important diseases of rice, due to its broad geographic distribution and capacity to destroy the crop. This disease is a challenge to rice farmers and one of the factors which limit rice yield, especially in the Central Region of Brazil, which is considered an area of high genetic diversity of the pathogen. In this region, rice blast resistance has been overcome only one or two years after a new resistant cultivar is commercially released. One of the objectives of the present work was to map blast resistance genes in the rice genome in order to intensify the development of strategies to use genes conferring major or partial resistance by breeding programs. In this study, the evaluation of the phenotypic interaction between M. oryzae isolates collected in the Araguaia River Valley and parents of a population of recombinant inbred lines (RIL) allowed the identification of isolate 623, physiological race IA-1, which is able to induce incompatibility reaction (resistance) in the traditional tropical japonica variety Puteca, and compatibility (susceptibility) in the traditional tropical japonica variety Chorinho. DNA polymorphism analysis in 192 microsatellite and SNP loci, distributed in the rice genome, allowed the construction of a genetic map with 1074.19 cM and average recombination distance of 5.59 cM between markers. Interaction phenotype and linkage analysis allowed the identification of microsatellite locus RM7213, located near the centromere region of chromosome 6, significantly associated with resistance to M. oryzae 623. This gene was temporarily called Pi-Put1. The region of maker RM7213 has a cluster of blast resistant genes, some of them with broad resistance to blast races. This region can be further explored by breeding programs in order to obtain new cultivars resistant to the pathogen. One of the alternatives for the development of blast resistant cultivars is indirect gene pyramiding, based on the exploration near-isogenic lines with different resistant genes to compose multilines.

Abstract

Developing and using disease-resistant varieties of cereal are one of the most effective approaches for combating yield loss. The understanding of how such the cereal varieties would affect the microbiome associated with the host, which can be the key determinant to the health and productivity of cereal grains, is lacking. Finding microbes that correlated with different resistance cereal and geographic location will assist in defining a set of core bioindicators reflecting grain and soil health and safety. In this study, grain and rhizosphere samples from resistant varieties of wheat (Triticum aestivum L., resistant to Fusarium Head Blight) and rice (Oryza sativa L., resistant to rice blast) were collected from seven provinces in China during the harvest seasons 2015/2016. The fungal and bacterial flora was recovered by sequencing the amplicons of internal transcribed spacer (ITS) and 16S rRNA gene region, respectively, using Illumina MiSeq sequencing technology. The core microbiota of rice grains are species from genera Nigrospora, Occultifur, Sakaguchia and Ustilaginodidea while that of wheat grains are Cystofilobasidium, Rhizopus and Sclerostagonospora. The distinct microbiota profile associated with wheat or rice reflects host-mediated selection of microbiomes, which is also shaped by geography, for example some important rice pathogens, including Cercospora, Curvularia, Pyricularia and Ustilaginoidea were significantly more frequently recognized in grain samples collected in Central and Southern regions of China than samples collected in Northeast China. The occurrence frequency of these pathogenic fungi in different areas of China can be used in making strategy to control the crop diseases and improve yield and quality of rice and wheat grains.