Biology subjects

Maiale, S. J.

Publications and source records attributed to Maiale, S. J..

5 recordsLinked to original sources

bioRxiv2023

Field and genetic evidence support the photosynthetic performance index (PIABS) as an indicator of rice grain yield

The effective increase of the rice breeding process for grain yield could be sustained by developing efficient tools to accelerate plant selection through the rapid determination of reliable predictors. Here, we have described different associations between grain yield and photosynthetic parameters simply and fast obtainable by a non-invasive technique in flag leaf during the anthesis stage. Among the analyzed photosynthetic parameters, the photosynthetic performance index (PIABS) stood out for its strong association with grain yield. A genome-wide association analysis determined in plants from a rice diversity panel at tillering stage indicated the presence of a quantitative trait locus on chromosome 9 characterized by a set of candidate chloroplastic genes with contrasting haplotypes for PIABS. An analysis of these haplotypes indicated a separation into two groups. One with haplotypes linked to high values of PIABS, which were associated almost exclusively with Japonica spp. subpopulations, and another with haplotypes linked to low values of PIABS, which were associated exclusively with Indica spp. subpopulations. Genotypes of the Japonica spp. subpopulations showed high values in panicle weight, a yield components parameter, compared with the Indica spp. subpopulations genotypes. The results of this work suggested that PIABS could be an early predictor of grain yield at the tillering stage in rice breeding processes.

plant biology↗

bioRxiv2023

Rice plants alter their yield component parameters based on their tolerance to low temperatures determined by a non-invasive method during the vegetative stage

The first rice phenological stages are commonly subjected to low temperatures (LT) in temperate crop areas. Here, plants of rice genotypes were analyzed according to their LT tolerance at seedling stage, using a realistic experimental temperatures range, and measuring quantitative and operator-independent parameters, fast-obtainable by non-invasive techniques. The ratios between values of these parameters determined in plants under LT condition with respect to the control condition were statistically analyzed. We have found a discriminant formula based on two parameters that allowed to differentiate between genotypes previously described as tolerant and sensitive to LT, with a very low general classification error. The application of the discriminant formula to score plants under LT, using all genotypes from the Rice Diversity Panel 1 which comprehensively represents the genetic variability of the O. sativa species, resulted in LT tolerance levels of its subspecies and subpopulations consistent with previous reports. In turn, a strong association between the LT tolerance score at the seedling stage and the panicle weight in plants under field LT during the vegetative stage, suggested that this scoring could be used as an indirect selection factor of genotypes with good yield traits and suited to LT prone environments.

plant biology↗

bioRxiv2021

Stem canker caused by Phomopsis spp. induces changes in polyamine levels and chlorophyll fluorescence parameters in pecan leaves

Pecan plants are attacked by the fungus Phomopsis spp. that causes stem canker, a serious and emerging disease in commercial orchards. Stem canker, which has been reported in several countries, negatively affects tree canopy health, eventually leading to production losses. The purpose of this study was to inquire into the physiology of pecan plants under stem canker attack by Phomopsis spp. To this end, pecan plants were inoculated with an isolate of Phomopsis spp. and several parameters, such as polyamines, proline, sugars, starch, chlorophyll fluorescence and canopy temperature were analysed. Under artificial inoculation, a high disease incidence was observed with symptoms similar to those in plants showing stem canker under field conditions. Furthermore, the infected stem showed dead tissue with brown necrotic discolouration in the xylem tissue. The free polyamines putrescine, spermidine, and spermine were detected and their levels decreased as leaves aged in the infected plants with respect to the controls. Chlorophyll fluorescence parameters, such as Sm, {psi}EO, and QbRC decreased under plant infection and therefore the K-band increased. Canopy temperature and proline content increased in the infected plants with respect to the controls while sugar content decreased. These data suggest that stem canker caused by Phomopsis spp. induces physiological changes that are similar to those observed in plants under drought stress. To our knowledge, this is the first study that documents the physiological and biochemical effects derived from pecan-Phomopsis interaction.

pathology↗

bioRxiv2020

Genetic structure of Photosystem II functionality in rice unraveled by GWAS analysis

Rice production is a particularly important crop for the half-world population. Therefore, knowledge about which genes are implicated in the functionality of the Photosystem II, that are still poorly explored could collaborate in the assisted selection of rice improving. In the present study, we applied Genome wide Association Studies of PSII chlorophyll fluorescence under two contrasting environmental conditions in 283 rice accessions highly diverse. A total of 110 significant association SNP-phenotype were observed, and 69 quantitative trait loci identified with a total of 157 genes, of which 38 were highly significant, mapped spread out through rice genome. These underlying regions are enriched in genes related to biotic and abiotic stresses, transcription factors, Calvin cycle, senescence, and grain characters. The correlations analyses PSII chlorophyll fluorescence parameters and some panicle characteristics found here suggest the possibility of developing molecular markers to assist the breeding programs that improve photosynthesis and yield in rice. HighlightThe genetic structure of the Photosystem II functionality in rice was studied by using genome-wide association through chlorophyll fluorescence.

plant biology↗

bioRxiv2019

The fungal endophyte Fusarium solani provokes differential effects on the energy balance of two Lotus species

Background and aimsThe interactions established between plants and endophytic fungi span a continuum from beneficial to pathogenic associations. The aim of this work was to explore the mechanisms underlying the potentially beneficial effects provoked by a fungal strain in legume species of the genus Lotus.\n\nMethodsThe ability to solubilise phosphorous was evaluated in nine fungal strains isolated from roots of L. tenuis. A selected strain was further assessed for its ability to colonize plant roots in different Lotus species. The effects of the two interactions were assessed by analysis of the photosynthesis, sugar amount, and macronutrient status of leaves and roots.\n\nResultsA fungal isolate identified as Fusarium solani shows the highest phosphate-solubilisation activity and grows endophytically in roots of L. japonicus and L. tenuis. Fungal invasion enhances plant growth in L. japonicus but provokes a contrasting effect in L. tenuis. Photosynthesis, sugars and K content showed a differential effect in both plant species.\n\nConclusionsOur results indicate neither of the plant species evaluated in this work were significantly stressed by F. solani. Thus, the differential responses observed are due to distinct mechanisms involving photosynthesis, potassium homeostasis, and carbohydrate metabolism that are employed by plants to maintain fitness during the endophytic interaction.

microbiology↗