The influence of phylogeny and ecology on root, shoot and plant ionomes of 14 native Brazilian species

Chronic ozone exposure impairs the mineral nutrition of date palm (Phoenix dactylifera) seedlings

Chronic ozone (O₃) exposure in the atmosphere preferentially disturbs metabolic processes in the roots rather than the shoot as a consequence of reduced photosynthesis and carbohydrate allocation from the leaves to the roots. The aim of the present study was to elucidate if mineral nutrition is also impaired by chronic O₃ exposure. For this purpose, date palm (Phoenix dactylifera) plants were fumigated with ambient, 1.5 × ambient and 2 × ambient O₃ in a free air controlled exposure (FACE) system for one growing season and concentrations of major nutrients were analyzed in leaves and roots. In addition, concentrations of C and N and their partitioning between different metabolic C and N pools were determined in both organs. The results showed that calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), sodium (Na) and potassium (K) acquisition by roots was diminished by O₃ exposure of the shoot. For Ca, Mg, Fe and Zn reduced uptake by the roots was combined with reduced allocation to the shoot, resulting in a decline of foliar concentrations; for Na and K, allocation to the shoot was maintained at the expense of the roots. Thus, elevated O₃ impaired both mineral uptake by the roots and partitioning of minerals between roots and shoots, but in an element specific way. Thereby, elevated O₃ affected roots and shoots differently already after one growing season. However, considerable changes in total C and N concentrations and their partitioning between different metabolic pools upon chronic O₃ exposure were not observed in either leaves or roots, except for reduced foliar lignin concentrations at 2 × ambient O₃. Significant differences in these parameters were shown between leaves and roots independent of O₃ application. The physiological consequences of the effects of chronic O₃ exposure on mineral acquisition and partitioning between leaves and roots are discussed.

Leaf elemental composition analysis in spider plant [Gynandropsis gynandra L. (Briq.)] differentiates three nutritional groups

Understanding the genetic variability within a plant species is paramount in implementing a successful breeding program. Spider plant (Gynandropsis gynandra) is an orphan leafy vegetable and an extraordinary source of vitamins, secondary metabolites and minerals, representing an important resource for combatting malnutrition. However, an evaluation of the leaf elemental composition, using a worldwide germplasm collection to inform breeding programs and the species valorization in human nutrition is still lacking. The present study aimed to profile the leaf elemental composition of G. gynandra and depict any potential geographical signature using a collection of 70 advanced lines derived from accessions originating from Asia and Eastern, Southern and West Africa. The collection was grown in a greenhouse using a 9 × 8 alpha lattice design with two replications in 2020 and 2021. Inductively coupled plasma-optical emission spectrometry was used to profile nine minerals contents. A significant difference (p < 0.05) was observed among the lines for all nine minerals. Microelements such as iron, zinc, copper and manganese contents ranged from 12.59-430.72, 16.98-166.58, 19.04-955.71, 5.39-25.10 mg kg^-1 dry weight, respectively, while the concentrations of macroelements such as potassium, calcium, phosphorus and magnesium varied in the ranges of 9992.27-49854.23, 8252.80-33681.21, 3633.55-14216.16, 2068.03-12475.60 mg kg^-1 dry weight, respectively. Significant and positive correlations were observed between iron and zinc and calcium and magnesium. Zinc, calcium, phosphorus, copper, magnesium, and manganese represented landmark elements in the genotypes. Eastern and Southern African genotypes were clustered together in group 1 with higher phosphorus, copper and zinc contents than Asian and West African lines, which clustered in group 2 and were characterized by higher calcium, magnesium and manganese contents. An additional outstanding group 3 of six genotypes was identified with high iron, zinc, magnesium, manganese and calcium contents and potential candidates for cultivar release. The genotype × year interaction variance was greater than the genotypic variance, which might translate to phenotypic plasticity in the species. Broad-sense heritability ranged from low to high and was element-specific. The present results reveal the leaf minerals diversity in spider plant and represent a baseline for implementing a minerals-based breeding program for human nutrition.

Endorsement and phylogenetic analysis of some Fabaceae plants based on DNA barcoding

Background

DNA barcoding have been considered as a tool to facilitate species identification based on its simplicity and high-level accuracy in compression to the complexity and subjective biases linked to morphological identification of taxa. MaturaseK gene (MatK gene) of the chloroplast is very vital in the plant system which is involved in the group II intron splicing. The main objective of this study is to determine the relative utility of the “MatK” chloroplast gene for barcoding in 15 legume as a tool to facilitate species identification based on their simplicity and high-level accuracy linked to morphological identification of taxa.

Methods and Results

MatK gene sequences were submitted to GenBank and the accession numbers were obtained with sequence length ranging from 730 to 1545 nucleotides. These DNA sequences were aligned with database sequence using PROMALS server, Clustal Omega server and Bioedit program. Maximum likelihood and neighbor-joining algorithms were employed for constructing phylogeny. Overall, these results indicated that the phylogenetic tree analysis and the evolutionary distances of an individual dataset of each species were agreed with a phylogenetic tree of all each other consisting of two clades, the first clade comprising (Enterolobium contortisiliquum, Albizia lebbek), Acacia saligna, Leucaena leucocephala, Dichrostachys Cinerea, (Delonix regia, Parkinsonia aculeata), (Senna surattensis, Cassia fistula, Cassia javanica) and Schotia brachypetala were more closely to each other, respectively. The remaining four species of Erythrina humeana, (Sophora secundiflora, Dalbergia Sissoo, Tipuana Tipu) constituted the second clade.

Conclusion

Moreover, their sequences could be successfully utilized in single nucleotide polymorphism or as part of the sequence as DNA fragment analysis utilizing polymerase chain reaction in plant systematic. Therefore, MatK gene is considered promising a candidate for DNA barcoding in the plant family Fabaceae and provides a clear relationship between the families.

The X-ray fluorescence screening of multiple elements in herbarium specimens from the Neotropical region reveals new records of metal accumulation in plants

Plants have developed a diversity of strategies to take up and store essential metals in order to colonize various types of soils including mineralized soils. Yet, our knowledge of the capacity of plant species to accumulate metals is still fragmentary across the plant kingdom. In this study, we have used the X-Ray Fluorescence technology to analyze metal concentration in a wide diversity of species of the Neotropical flora that was not extensively investigated so far. In total, we screened more than 11 000 specimens representing about 5000 species from herbaria in Paris and Cuba. Our study provides a large overview of the accumulation of metals such as manganese, zinc and nickel in the Neotropical flora. We report 30 new nickel hyperaccumulating species from Cuba, including the first records in the families Connaraceae, Melastomataceae, Polygonaceae, Santalaceae and Urticaceae. We also identified the first species from this region of the world that can be considered as manganese hyperaccumulators in the genera Lomatia (Proteaceae), Calycogonium (Melastomataceae), Ilex (Aquifoliaceae), Morella (Myricaceae) and Pimenta (Myrtaceae). Finally, we report the first zinc hyperaccumulator, Rinorea multivenosa (Violaceae), from the Amazonas region. The identification of species able to accumulate high amounts of metals will become instrumental to support the development of phytotechnologies in order to limit the impact of soil metal pollution in this region of the world.

Ionomic Responses of Local Plant Species to Natural Edaphic Mineral Variations

Leaf ionome indicates plant phylogenetic evolution and responses to environmental stress, which is a critical influential factor to the structure of species populations in local edaphic sites. However, little is known about leaf ionomic responses of local plant species to natural edaphic mineral variations. In the present study, all plant species and soil samples from a total of 80 soil sites in Shiozuka Highland were collected for multi-elemental analysis. Ioniomic data of species were used for statistical analysis, representing 24 species and 10 families. Specific preferences to ionomic accumulation in plants were obviously affected by the phylogeny, whereas edaphic impacts were also strong but limited within the phylogenetic preset. Correlations among elements resulted from not only elemental synergy and competition but also the adaptive evolution to withstand environmental stresses. Furthermore, ionomic differences of plant families were mainly derived from non-essential elements. The majority of variations in leaf ionome is undoubtedly regulated by evolutionary factors, but externalities, especially environmental stresses also have an important regulating function for landscape formation, determining that the contributions of each factor to ionomic variations of plant species for adaptation to environmental stress provides a new insight for further research on ionomic responses of ecological speciation to environmental perturbations and their corresponding adaptive evolutions.

Genetic dissection of the shoot and root ionomes of Brassica napus grown with contrasting phosphate supplies

BACKGROUND AND AIMS

Mineral elements have many essential and beneficial functions in plants. Phosphorus (P) deficiency can result in changes in the ionomes of plant organs. The aims of this study were to characterize the effects of P supply on the ionomes of shoots and roots, and to identify chromosomal quantitative trait loci (QTLs) for shoot and root ionomic traits, as well as those affecting the partitioning of mineral elements between shoot and root in Brassica napus grown with contrasting P supplies.

METHODS

Shoot and root concentrations of 11 mineral elements (B, Ca, Cu, Fe, K, Mg, Mn, Na, P, S and Zn) were investigated by inductively coupled plasma optical emission spectrometry (ICP-OES) in a Brassica napus double haploid population grown at an optimal (OP) and a low phosphorus supply (LP) in an agar system. Shoot, root and plant contents, and the partitioning of mineral elements between shoot and root were calculated.

KEY RESULTS

The tissue concentrations of B, Ca, Cu, K, Mg, Mn, Na, P and Zn were reduced by P starvation, while the concentration of Fe was increased by P starvation in the BnaTNDH population. A total of 133 and 123 QTLs for shoot and root ionomic traits were identified at OP and LP, respectively. A major QTL cluster on chromosome C07 had a significant effect on shoot Mg and S concentrations at LP and was narrowed down to a 2.1 Mb region using an advanced backcross population.

CONCLUSIONS

The tissue concentration and partitioning of each mineral element was affected differently by P starvation. There was a significant difference in mineral element composition between shoots and roots. Identification of the genes underlying these QTLs will enhance our understanding of processes affecting the uptake and partitioning of mineral elements in Brassica napus.