Brazilian Journal of Botany最新文献

The present paper discusses the growth responses of Chenopodium album L. to salinity and its possible use in the context of reducing salt stress considering the fact that soil salinity is a major problem caused by climate change and anthropogenic activities. Salt tolerance potential and phytodesalination ability of C. album growing in the same salt-affected soil of two different textures (clay and clay loam) over a range of salinity [non-saline (EC_e is 0–2 dS m⁻¹), slightly salinized (EC_e is 2–4 dS m⁻¹), moderately salinized (EC_e is 4–8 dS m⁻¹), highly salinized (EC_e is 8–16 dS m⁻¹), and extremely heavily salinized (EC_e > 16 dS m⁻¹) of two different rates, extreme₁ (EC_e is 16–20 dS m⁻¹) and extreme₂ (EC_e is 25–30 dS m⁻¹)], were studied and compared. According to investigated growth traits, the plants growing in clay soils revealed better adaptation reaction than the plants growing in clay loam soils, and an increase in the main part of examined indices was observed until reaching high degree of salinity, after which the plants demonstrated symptoms of stress in all growth parameters. C. album, maintaining the survivability in parallel with increase in salinity, intensively accumulated toxic ions like Na⁺ and Cl⁻ that promoted the feasibility of this plant for phytodesalination of saline degraded soils. The results obtained can contribute to a deeper comprehension of an alternative phytotechnology for remediation of saline soils by tolerant and productive plant C. album to provide favorable conditions for growth and production of various cash crops.

Researching the photosynthetic characteristics based on the whole chloroplast genome sequence of Camellia osmantha cv ‘yidan’ is important for improving production. We sequenced and analyzed the chloroplast (cp) genomes of C. osmantha cv ‘yidan’. The total cp genome length was 156,981 bp. The cp genomes included 134 genes encoding 81 proteins, 39 transfer RNAs, 8 ribosomal RNAs, and 6 genes with unknown functions. In total, 50 repeat sequences were identified in C. osmantha cv ‘yidan’ cp genomes. Phylogenetic analysis showed that C. osmantha cv ‘yidan’ is more closely related to Camellia vietnamensis cv ‘hongguo’ and Camellia oleifera cv ‘cenruan 3’ than to Camellia semiserrata cv ‘hongyu 1’. Our complete assembly of four Camellia cp genomes may contribute to breeding for high oil content plants and further biological discoveries. The results of this study provide a basis for the assembly of the entire chloroplast genome of C. osmantha cv ‘yidan’.

Quinoa grains are nutritionally rich and balanced, rich in protein, starch, VB1, folic acid, minerals (Ca, Zn, Fe) and other nutrients and grow at high altitude (> 3500 m above sea level) all year round; it is subjected to drought, low temperature, salt and other abiotic stresses during its growth and development; basic helix–loop–helix (bHLH) family is the second largest gene family in plants and is involved in many biological processes such as plant growth, development, metabolism and resistance to abiotic stress. In bioinformatics and expression analysis of glutathione S-transferase (GST) gene in quinoa in this study, 114 CqGST genes were identified from the whole genome of quinoa by bioinformatics methods. The phylogenetic tree showed that 114 CqGST genes were divided into seven subgroups. Phylogenetic analysis of these genes suggested that tandem and fragment replication events played a key role in the expansion of the CqGSTs gene family, and the CqGST genes may have undergone strong purification selection during the evolution process. Analysis of salt-treated transcriptome from the roots of salt-tolerant and salt-sensitive quinoa cultivars showed that salt treatment induced changes in the expression levels of CqGSTs genes. By comparing the sequences of the bHLH gene family members of Arabidopsis thaliana and the bHLH transcription factor family members Quinoa most of the bHLH transcription factors of quinoa have high homology with that of Arabidopsis thaliana. The number of exons contained in CqGST gene ranged from 1 to 14, among which CqGSTL2 contained 14 exons, indicating that CqGSTL2 contained 14 exons, the gene with the highest number of exons, respectively. The number of exons in six CqGSTZ members was significantly different, including three members have two exons and three have nine exons. Studies on chromosome distribution are that except for no CqGST gene on chromosome 09, all the other chromosomes were identical; there was CqGST gene distribution, and chromosome 07 contains 20 CqGST genes, which was one of CqGST gene distribution. CqGSTL1 and CqGSTU1 cannot locate specific chromosomes due to the quality of the genome. In order to explore the expression pattern of GST gene, different tissues or RNA-seq data of Quinoa from various developmental stages of organs were systematically analyzed. In class U, CqGSTU22, CqGSTU67, CqGSTU43, CqGSTU42, CqGSTU15, in class L, CqGSTL1 and CqGSTL5, in class Z, CqGSTZ5, DHAR class CqDHAR2 and CqDHAR3 were strongly expressed in various varieties tissues and organs. The CqGST, U66, CqGSTF20 and CqGSTF23 were not expressed in the 11 tissues or organs tested. Related to the temporal and spatial expression patterns of these genes, there were multiple genes in each type in the s

Germination of many cacti across the Americas is light-dependent, but less has been explored regarding biochemical and morphophysiological alterations during germination and initial growth under different light spectra. Red and blue wavelengths, for instance, are predominantly absorbed by photosynthetic pigments, regulating plant growth. This study aimed to characterize physiological, anatomical and biochemical features of the mandacaru cactus (Cereus jamacaru DC.), an overexploited cactus crop from the Brazilian Caatinga, during germination and initial growth under white, red, and blue lights. Germination was tested under the three light treatments; the emerged seedlings were then cultivated under the same conditions. Seedling height and diameter were registered at 45, 60, 75, and 90 days after sowing. Photosynthetic pigments and total soluble sugars were quantified over time; anatomical analyses of the cladodes were also performed. White and red lights promoted the highest germination percentages (98–97%), with a decrease in the blue light (56%). Seedling height increased under the red light (35–36 mm) compared to the other treatments. Blue light tended to promote greater contents of chlorophylls and carotenoids. Total soluble sugars were greater in the blue light until 60 days, but equal among treatments at 75 and 90 days. Calcium oxalate crystals and amyloplasts were observed at 45 days in all treatments. This study shows contrasting physiological responses between light quality treatments, mostly related to the higher energy dissipation required under the blue wavelength. Future research should investigate seedling biomass production and relative growth rates, including comparisons with other populations of the mandacaru cactus.

The deposition of incompatible pollen grains in the stigma can interfere with the performance of compatible pollen grains and compromise the reproductive success of the species in the community. Ipomoea asarifolia, a self-incompatible species, occurs in sympathy with I. brasiliana, sharing pollinators, but without hybrid formation. However, this condition favors the deposition of auto pollen and interspecific pollen in the stigma, which can compromise the reproductive success of the species in the community. Given this, we investigated the influence of incompatible intra- and interspecific pollen grains on their reproductive success of I. asarifolia, based on analyses of natural pollination and controlled experiments. Our hypothesis is that the presence of incompatible pollen grains in the stigma negatively interferes with the formation of fruits and seeds in I. asarifolia. Fruit yield was significantly higher in manual cross-pollination than in natural pollination and mixed pollination experiments of compatible (intraspecific: cross-pollinated pollen) and incompatible (intraspecific: self-pollen and interspecific: pollen of I. brasiliana) pollens. Seed yield was significantly higher in cross-pollination than between the two mixed pollination experiments. Seed production was not significantly different between cross-pollination and natural pollination, nor between natural pollination and mixed pollination experiments. However, fruit and seed production was higher in cross-pollination than in other situations. And experiments with incompatible amounts of pollens do not form fruits. Few fruits and seeds are formed in the presence of incompatible pollens (intra and interspecific), which may be interfering with reproductive success in I. asarifolia, especially in the long term. We reinforce the importance of the selection of reproductive displacement in the species to minimize the flow of incompatible pollens and their reproductive interferences.

The interaction between polyamine content and antioxidant activity in plants can confer resistance to environmental stress. In this study, polyamines and antioxidant activities in T₂-generation transgenic plants overexpressing the MsSAMS (Miscanthus sinensis S-adenosylmethionine synthetase) gene were studied. First, the results of plant length, leaf length, leaf width, leaf number, stem diameter, and chlorophyll content in the T₂-generation transgenic plants into which the MsSAMS gene was inserted showed that there were only slight differences in the agricultural phenotype, and no significant difference was observed. Result of the analyses of polyamine-based components: putrescine, spermidine, and spermine showed that there was no detectable amount of putrescine in the control group, whereas in the T6 line, it was 399.14 ± 15.46 μg/g FW. Spermidine level was 1497.16 ± 53.28 μg/g FW and 146.97 ± 12.58 μg/g FW in the T17 and T9 lines of transgenic plants, respectively. Furthermore, free radical scavenging activity was measured using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS [2,2′-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid)] assays. T17 line showed the highest antioxidant activity (1974.85 ± 18.06 μg/mL) in DPPH assay, whereas T6 line showed the highest activity (7390.12 ± 67.39 μg/mL) in ABTS assay. Results of the analysis of the total phenol and flavonoid content of the transgenic plants revealed that the T6 line and T2 line showed the highest values, respectively (208.20 ± 3.36 mg GAE/g and 22.07 ± 0.49 mg QE/g, respectively). These results suggest that the MsSAMS gene plays a role in enhancing antioxidant activity by increasing polyamine content.

The sycamore lace bug Corythucha ciliata (say) is the most important pest attacked the London planetree Platanus acerifolia worldwide. We propose that plant cytochrome P450s (CYP450s) are important and play key roles in P. acerifolia and C. ciliata interactions. Therefore, the identification of transcriptionally active CYP450 genes is considered essential for revealing the mechanisms involved in their interactions. So far, the CYP450 genes of P. acerifolia have not yet been reported. In this study, we identified and characterized 96 CYP450 genes in P. acerifolia. These genes were categorized into 8 clans, 41 families, and 60 subfamilies. Notably, 48 genes demonstrated a strong negative selection when compared with the CYP450 genes of Arabidopsis thaliana. The results of post-feeding induction of P. acerifolia by C. ciliata revealed ten CYP450 genes, which exhibited significant up-regulation. Gene expression levels of several identified CYP450 genes were validated by quantitative RT- PCR. Further, a putative allene oxide synthase gene encoding the key enzyme involved in the jasmonic acid biosynthesis (PaCYP74A187) was cloned, homology modeled, and subjected to molecular docking analysis. We propose PaCYP74A187 as a key candidate CYP450 gene in P. acerifolia induced by C. ciliata damage, altogether our findings enhance comprehensive understanding of the mechanisms associated with insect-plant interactions that will undoubtedly offer new targets for controlling C. ciliata populations.

Black gram is one of the important legume crops cultivated in the world, particularly in India mainly for protein requirements. It is grown mostly as a fallow crop in rotation with cereals. However, under saline stress conditions, the growth of the plants is reduced, ultimately resulting in a reduction in yield. The present investigations were carried out to evaluate the extent of genetic divergence and character association in 48 black gram genotypes for eleven biometric characters. In addition, the saline-tolerant genotypes were assessed in vitro. The analysis of variance revealed significant differences present in all the genotypes and showed a considerable amount of saline tolerance in the genotypes. Genetic diversity analysis using microsatellite markers revealed that out of a total of 21 SSR markers, 13 were polymorphic which revealed 47 alleles in forty-eight black gram genotypes with an average of 3 alleles per locus. Cluster analysis revealed that among the 21 markers used, 13 were found to be polymorphic with a transferability rate of 83%. From the present study, three genotypes, namely AUB 9, AUB 14 and AUB 20, were identified as saline-tolerant and were also confirmed by biometric and molecular analysis.

Miconia Ruiz & Pav. (Melastomataceae) is the seventh largest genus of flowering plants, but despite the great diversity of species (ca. 1900), no genome size (GS) studies have been published on the group. Studies have shown that GS can strongly predict phenotypic characteristics such as guard cell length, stomatal density, and epidermal cell area. As more genome sizes become available, a more comprehensive understanding of the role that GS variation plays in cellular characteristics emerges. Here, for the first time, we estimate GS by flow cytometry in four Miconia species, Miconia australis (Cham.) R. Goldenb., Miconia hyemalis St. Hil. & Naud. ex Naud., Miconia sellowiana (DC.) Naudin, and Miconia nianga (DC.) R.Goldenb.). Subsequently, we carried out a comparative analysis of the relationship between GS and three phenotypic characteristics: guard cell length, stomatal density, and epidermal cell area. The estimated GS ranged from 0.56 to 1.2 pg, and this variation may be attributed to the distinct reproductive modes among the species analyzed. We found a strong positive correlation between GS and guard cell length (r² = 0.92) and a low correlation in stomatal density and epidermal cell area (r² = 0.07 and 0.06, respectively). In this pioneering study, we provide some conclusions or speculations, and point to new questions yet to be explored in Miconia.

Our aim was to test the hypothesis that root growth of ‘Mandarin’ lime—a drought tolerant citrus rootstock—under water deficit is associated with higher nitric oxide (NO) content in roots. As a reference, ‘Swingle’ citrumelo was compared with ‘Mandarin’ lime, two well-known citrus rootstocks. ‘Valencia’ sweet orange plants grafted on ‘Mandarin’ lime or ‘Swingle’ citrumelo were kept well-hydrated or grown under water withholding. After 14 days of water deficit, root morphology was evaluated, and leaf and root samples were collected for NO analysis. Under low water availability, ‘Mandarin’ lime exhibited higher root NO content and root growth than ‘Swingle’ citrumelo. Indeed, NO seems to modulate not only root biomass accumulation but also root morphology as higher NO was associated with large increase in root length and area. Such findings suggest that root NO content is a relevant marker for early screening of drought-tolerant citrus genotypes. As a novelty, we show that ‘Mandarin’ lime drought tolerance is significantly associated with root NO content.