Genome-wide association study suggests an independent genetic basis of zinc and cadmium concentrations in fresh sweet corn kernels

Topological data analysis expands the genotype to phenotype map for 3D maize root system architecture

A central goal of biology is to understand how genetic variation produces phenotypic variation, which has been described as a genotype to phenotype (G to P) map. The plant form is continuously shaped by intrinsic developmental and extrinsic environmental inputs, and therefore plant phenomes are highly multivariate and require comprehensive approaches to fully quantify. Yet a common assumption in plant phenotyping efforts is that a few pre-selected measurements can adequately describe the relevant phenome space. Our poor understanding of the genetic basis of root system architecture is at least partially a result of this incongruence. Root systems are complex 3D structures that are most often studied as 2D representations measured with relatively simple univariate traits. In prior work, we showed that persistent homology, a topological data analysis method that does not pre-suppose the salient features of the data, could expand the phenotypic trait space and identify new G to P relations from a commonly used 2D root phenotyping platform. Here we extend the work to entire 3D root system architectures of maize seedlings from a mapping population that was designed to understand the genetic basis of maize-nitrogen relations. Using a panel of 84 univariate traits, persistent homology methods developed for 3D branching, and multivariate vectors of the collective trait space, we found that each method captures distinct information about root system variation as evidenced by the majority of non-overlapping QTL, and hence that root phenotypic trait space is not easily exhausted. The work offers a data-driven method for assessing 3D root structure and highlights the importance of non-canonical phenotypes for more accurate representations of the G to P map.

CaHMA1 promotes Cd accumulation in pepper fruit

The main planting areas for pepper (Capsicum sp.) are high in cadmium (Cd), which is the most prevalent heavy metal pollutant worldwide. Breeding pepper cultivars with low Cd levels can promote sustainable agricultural production and ensure the safety of pepper products. To identify breeding targets for reducing Cd accumulation in pepper fruits, we performed a genome-wide association study on 186 accessions. Polymorphisms were associated with fruit Cd content in a genomic region containing a homolog of Arabidopsis (Arabidopsis thaliana) Heavy metal-transporting ATPase 1 (HMA1) encoding a P-type ATPase. In two cultivars with contrasting Cd accumulation, transcriptome analysis revealed differentially expressed genes enriched for carbohydrate metabolism and photosynthesis in fruits with high Cd accumulation, and a Cd2+/Zn2+-exporting ATPase gene (HMA). Heterologous expression of CaHMA1 in yeast increases Cd sensitivity. Overexpression of CaHMA1 conferred a severe increase in Cd content in Arabidopsis plants, whereas reduced CaHMA1 expression in pepper fruits decreased Cd content. We propose that CaHMA1 expression may be an important component of the high Cd accumulation in pepper plants.

Fresh/High-Zinc Maize: A Promising Solution for Alleviating Zinc Deficiency through Significant Micronutrient Accumulation

Zinc deficiency poses a significant health challenge worldwide, particularly in regions where access to and the affordability of dietary diversity are limited. This research article presents a time course analysis of kernel development on the zinc content in maize kernels with different genetic backgrounds, including normal maize, quality protein maize, and high-zinc maize, grown at two locations. Zn concentrations during stage I were high, decreasing between stages II and IV and increasing during stages V to VII. High-zinc kernel genotypes, including those ones with high-quality protein genetic backgrounds, have higher contents of zinc and iron during the milky stage (fresh/green maize). The zinc and iron content in fresh maize differed depending on the genotype. By consuming fresh maize biofortified with zinc, up to 89% and 100% of EAR needs can be fulfilled for pregnant women and children. The results demonstrate that fresh high-zinc maize accumulates a substantial amount of this micronutrient, highlighting its potential as a valuable source for addressing zinc deficiency.

EFFECT OF PHYSICAL ACTIVITY ON HOMEOSTASIS IN PROFESSIONAL BASKETBALL PLAYERS ACCORDING TO GENDER DIFFERENCES

ABSTRACT Introduction One of the main problems of modern basketball physiology is maintaining high performance and improving its players’ physical condition. Changes in the athlete’s functional condition occur due to the transition of the physiological system from rest to stress, fatigue, and regeneration. Objective Clarify the effect of physical activity on homeostasis in athletes according to gender differences. Methods The methods of analysis and synthesis, comparative analysis, modeling, and logical analysis were applied. Results Positive and negative factors of the influence of physical activity on elementary homeostasis of professional basketball players depending on gender differences were assigned; also, the principles of selection of physical activity content and the methodological bases of application for use in training programs of professional basketball players were characterized. Conclusion The results of this study showed the need to control the elemental body homeostasis of basketball athletes and its changes in physical exertion conditions, considering personal characteristics and gender differences. Evidence level II; Therapeutic studies - outcomes research.

Transcriptome-wide association and prediction for carotenoids and tocochromanols in fresh sweet corn kernels

Sweet corn (Zea mays L.) is consistently one of the most highly consumed vegetables in the United States, providing a valuable opportunity to increase nutrient intake through biofortification. Significant variation for carotenoid (provitamin A, lutein, zeaxanthin) and tocochromanol (vitamin E, antioxidants) levels is present in temperate sweet corn germplasm, yet previous genome-wide association studies (GWAS) of these traits have been limited by low statistical power and mapping resolution. Here, we employed a high-quality transcriptomic dataset collected from fresh sweet corn kernels to conduct transcriptome-wide association studies (TWAS) and transcriptome prediction studies for 39 carotenoid and tocochromanol traits. In agreement with previous GWAS findings, TWAS detected significant associations for four causal genes, β-carotene hydroxylase (crtRB1), lycopene epsilon cyclase (lcyE), γ-tocopherol methyltransferase (vte4), and homogentisate geranylgeranyltransferase (hggt1) on a transcriptome-wide level. Pathway-level analysis revealed additional associations for deoxy-xylulose synthase2 (dxs2), diphosphocytidyl methyl erythritol synthase2 (dmes2), cytidine methyl kinase1 (cmk1), and geranylgeranyl hydrogenase1 (ggh1), of which, dmes2, cmk1, and ggh1 have not previously been identified through maize association studies. Evaluation of prediction models incorporating genome-wide markers and transcriptome-wide abundances revealed a trait-dependent benefit to the inclusion of both genomic and transcriptomic data over solely genomic data, but both transcriptome- and genome-wide datasets outperformed a priori candidate gene-targeted prediction models for most traits. Altogether, this study represents an important step toward understanding the role of regulatory variation in the accumulation of vitamins in fresh sweet corn kernels.