Department of Botany and Graduate Program in Cell and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
Dr. Felipe Ricachenevsky
Department of Botany and Graduate Program in Cell and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
The coronavirus disease 2019 (COVID-19) pandemic is altering dynamics in academia, and people juggling remote work and domestic demands – including childcare – have felt impacts on their productivity. Female authors have faced a decrease in paper submission rates since the beginning of the pandemic period. The reasons for this decline in women’s productivity need to be further investigated. Here, we analyzed the influence of gender, parenthood and race on academic productivity during the pandemic period based on a survey answered by 3,345 Brazilian academics from various knowledge areas and research institutions. Productivity was assessed by the ability to submit papers as planned and to meet deadlines during the initial period of social isolation in Brazil. The findings revealed that male academics – especially those without children – are the least affected group, whereas Black women and mothers are the most impacted groups. These impacts are likely a consequence of the well-known unequal division of domestic labor between men and women, which has been exacerbated during the pandemic. Additionally, our results highlight that racism strongly persists in academia, especially against Black women. The pandemic will have long-term effects on the career progression of the most affected groups. The results presented here are crucial for the development of actions and policies that aim to avoid further deepening the gender gap in academia.
Zinc (Zn) is an essential micronutrient for plants, playing catalytic or structural roles in enzymes, transcription factors, ribosomes and membranes. In humans, Zn deficiency is the second most common mineral nutritional disorder, affecting around 30% of the world’s population. People living in poverty usually have their diets based on milled cereals, which contain low Zn concentrations. Biofortification of crops is an attractive cost-effective solution for low mineral dietary intake. In order to increase the amounts of bioavailable Zn in crop edible portions, it is necessary to understand how plants take up, distribute and store Zn within their tissues, as well as to characterize potential candidate genes for biotechnological manipulation. The Metal Tolerance Proteins (MTP) were described as metal efflux transporters from the cytoplasm, transporting mainly Zn2+ but also Mn2+, Fe2+, Cd2+, Co2+ and Ni2+. Substrate specificity appears to be conserved in phylogenetically related proteins. MTPs characterized so far in plants have a role in general Zn homeostasis and tolerance to Zn excess; in tolerance to excess Mn and also in the response to Fe deficiency. More recently, the first MTPs in crop species have been functionally characterized. In Zn hyperaccumulator plants, the MTP1 protein is related to hypertolerance to elevated Zn concentrations. . Here, we review the current knowledge on this protein family, as well as biochemical functions and physiological roles of MTP transporters in Zn hyperaccumulators and non-accumulators. The potential applications of MTP transporters in biofortification efforts are discussed.
Heavy metal homeostasis is maintained in plant cells by specialized transporters which compartmentalize or efflux metal ions, maintaining cytosolic concentrations within a narrow range. OsMTP1 is a member of the cation diffusion facilitator (CDF)/metal tolerance protein (MTP) family of metal cation transporters in Oryza sativa, which is closely related to Arabidopsis thaliana MTP1. Functional complementation of the Arabidopsis T-DNA insertion mutant mtp1-1 demonstrates that OsMTP1 transports Zn in planta and localizes at the tonoplast. When heterologously expressed in the yeast mutant zrc1 cot1, OsMTP1 complemented its Zn hypersensitivity and was also localized to the vacuole. OsMTP1 alleviated, to some extent, the Co sensitivity of this mutant, rescued the Fe hypersensitivity of the ccc1 mutant at low Fe concentrations, and restored growth of the Cd-hypersensitive mutant ycf1 at low Cd concentrations. These results suggest that OsMTP1 transports Zn but also Co, Fe, and Cd, possibly with lower affinity. Site-directed mutagenesis studies revealed two substitutions in OsMTP1 that alter the transport function of this protein. OsMTP1 harbouring a substitution of Leu82 to a phenylalanine can still transport low levels of Zn, with an enhanced affinity for Fe and Co, and a gain of function for Mn. A substitution of His90 with an aspartic acid completely abolishes Zn transport but improves Fe transport in OsMTP1. These amino acid residues are important in determining substrate specificity and may be a starting point for refining transporter activity in possible biotechnological applications, such as biofortification and phytoremediation.