Catálogo de publicaciones - revistas

<jats:sec><jats:title>Introduction</jats:title><jats:p>Nitrogen is a major abiotic stress that affects plant productivity. Previous studies have shown that plant H+-pyrophosphatases (H+-PPases) enhance plant resistance to low nitrogen stress. However, the molecular mechanism underlying H+-PPase-mediated regulation of plant responses to low nitrogen stress is still unknown. In this study, we aimed to investigate the regulatory mechanism of AtAVP1 in response to low nitrogen stress.</jats:p></jats:sec><jats:sec><jats:title>Methods and Results</jats:title><jats:p>AtAVP1 in Arabidopsis thaliana and EdVP1 in Elymus dahuricus belong to the H+-PPase gene family. In this study, we found that AtAVP1 overexpression was more tolerant to low nitrogen stress than was wild type (WT), whereas the avp1-1 mutant was less tolerant to low nitrogen stress than WT. Plant height, root length, aboveground fresh and dry weights, and underground fresh and dry weights of EdVP1 overexpression wheat were considerably higher than those of SHI366 under low nitrogen treatment during the seedling stage. Two consecutive years of low nitrogen tolerance experiments in the field showed that grain yield and number of grains per spike of EdVP1 overexpression wheat were increased compared to those in SHI366, which indicated that EdVP1 conferred low nitrogen stress tolerance in the field. Furthermore, we screened interaction proteins in Arabidopsis; subcellular localization analysis demonstrated that AtAVP1 and Arabidopsis thaliana receptor-like protein kinase (AtRLK) were located on the plasma membrane. Yeast two-hybrid and luciferase complementary imaging assays showed that the AtRLK interacted with AtAVP1. Under low nitrogen stress, the Arabidopsis mutants rlk and avp1-1 had the same phenotypes.</jats:p></jats:sec><jats:sec><jats:title>Discussion</jats:title><jats:p>These results indicate that AtAVP1 regulates low nitrogen stress responses by interacting with AtRLK, which provides a novel insight into the regulatory pathway related to H+-pyrophosphatase function in plants.</jats:p></jats:sec>

<jats:sec><jats:title>Introduction</jats:title><jats:p>Overhead photoselective shade films installed in vineyards improve berry composition in hot grape-growing regions. The aim of the study was to evaluate the flavonoid and aroma profiles and composition of wines from Cabernet Sauvignon grapes (Vitis vinifera L.) treated with partial solar radiation exclusion.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Experimental design consisted in a randomized experiment with four shade films (D1, D3, D4, D5) with differing solar radiation spectra transmittance and compared to an uncovered control (C0) performed over two seasons (2021 and 2022) in Oakville (CA, USA). Berries were collected by hand at harvest and individual vinifications for each treatment and season were conducted in triplicates. Then, wine chemical composition, flavonoid and aromatic profiles were analyzed.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The wines from D4 treatment had greater color intensity and total phenolic index due to co-pigmentation with anthocyanins. Shade film wines D5 and D1 from the 2020 vintage demonstrated increased total anthocyanins in the hotter of the two experimental years. In 2021, reduced cluster temperatures optimized total anthocyanins in D4 wines. Reduced cluster temperatures modulated anthocyanin acylation, methylation and hydroxylation in shade film wines. Volatile aroma composition was analyzed using gas chromatography mass spectroscopy (GCMS) and D4 wines exhibited a more fruity and pleasant aroma profile than C0 wines.</jats:p></jats:sec><jats:sec><jats:title>Discussion</jats:title><jats:p>Results provided evidence that partial solar radiation exclusion in the vineyard using overhead shade films directly improved flavonoid and aroma profiles of resultant wines under hot vintage conditions, providing a tool for combatting air temperatures and warmer growing conditions associated with climate change.</jats:p></jats:sec>

<jats:sec><jats:title>Introduction</jats:title><jats:p>Extreme weather has occurred more frequently in recent decades, which results in more frequent drought disasters in the maize growing season. Severe drought often decreases remarkably plant growth and yield of maize, and even reduces significantly the quality of maize production, especially for waxy maize.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>To study the changes in plant growth, fresh ear yield, and fresh grain quality of waxy maize under water deficits occurring at different growth stages, and further strengthen the field water management of waxy maize, water deficit experiments were carried out under a rain shelter in 2019 and 2020. Water deficit treatments were imposed respectively at the V6–VT (D<jats:sub>V6–VT</jats:sub>), VT–R2 (D<jats:sub>VT–R2</jats:sub>), and R2–R3 (D<jats:sub>R2–R3</jats:sub>) stages of waxy maize, and treatment with non-water deficit in the whole growing season was taken as the control (CK). The lower limit of soil water content was 50% of field capacity for a water deficit period and 65% of field capacity for a non-water deficit period.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>In this study, water deficits imposed at V6–VT and VT–R2 stages decreased plant growth rate and leaf gas exchange parameters, accelerated leaf senescence, and limited ear growth of waxy maize, which resulted in 11.6% and 23.1% decreases in grains per ear, 19.4% and 7.3% declines in 100-grain weight, 20.3% and 14.2% losses in fresh ear yield in 2019 and 2020 growing seasons, respectively, while water deficit at R2–R3 stage had no significant effect on ear traits and fresh ear yield, but the fresh ear yield with husk of DR2–R3 decreased by 9.1% (P&amp;lt;0.05). The obvious water deficit imposed at the V6–VT and VT–R2 stages also lowered grain quality. Water deficits at the V6–VT and VT–R2 stages led to accelerated maturity, resulting in increased total protein, starch, and lysine content in grains at the R3 stage and decreased soluble sugar content. Principal component analysis revealed that when water deficits occurred in the waxy maize growing season, they firstly altered maize physiological processes, then affected ear characteristics and yield, and finally resulted in significant grain quality changes. In conclusion, a water deficit during V6–VT and VT–R2 not only reduced fresh ear yield but also adversely affected grain quality. However, water deficit during R2–R3 had little effect on total protein, starch, and soluble sugar content,but increased obviously lysine content.</jats:p></jats:sec><jats:sec><jats:title>Discussion</jats:title><jats:p>The above results suggested that avoiding serious water deficits at the V6–VT and VT–R2 stages of waxy maize while imposing a slight water deficit at the R2–R3 stage has not only little effects on fresh ear yield but also a remarkable improvement in grain quality.</jats:p></jats:sec>

<jats:p>Sexual dimorphism has commonly been found in many species. The phenotypes of <jats:italic>Salix matsudana</jats:italic> females and males are different under salinity stress. An F<jats:sub>1</jats:sub> population was selected to compare the differences between males and females. As a result, males showed stronger roots and heavier dry weights than females. The unique molecular mechanisms of males and females under salinity stress were further analyzed based on the root transcriptome of males and females. Both males and females up-regulated systemic acquired resistance genes, such as <jats:italic>ADH</jats:italic> and oxygenase-related genes, to resist salt. Moreover, many other abiotic stress response genes were up-regulated in males to adjust to salinity stress, while females showed more down-regulation of nitrogen metabolism-related genes to decrease the harm from salinity stress. The research on salinity tolerance in <jats:italic>Salix matsudana</jats:italic> males and females would help to further understand sexual dimorphism under selection pressure and provide benefits to the ecological environment.</jats:p>

<jats:p>Pullulanase (EC 3.2.1.41, PUL), a debranching enzyme belonging to glycoside hydrolase family 13 subfamily 13, catalyses the cleavage of α-1,6 linkages of pullulan and β-limit dextrin. The present work studied PUL from cassava <jats:italic>Manihot esculenta</jats:italic> Crantz (<jats:italic>Me</jats:italic>PUL) tubers, an important economic crop. The <jats:italic>Mepul</jats:italic> gene was successfully cloned and expressed in <jats:italic>E. coli</jats:italic> and r<jats:italic>Me</jats:italic>PUL was biochemically characterised. <jats:italic>Me</jats:italic>PUL was present as monomer and homodimer, as judged by apparent mass of ~ 84 - 197 kDa by gel permeation chromatography analysis. Optimal pH and temperature were at pH 6.0 and 50 °C, and enzyme activity was enhanced by the addition of Ca<jats:sup>2+</jats:sup> ions. Pullulan is the most favourable substrate for r<jats:italic>Me</jats:italic>PUL, followed by β-limit dextrin. Additionally, maltooligosaccharides were potential allosteric modulators of r<jats:italic>Me</jats:italic>PUL. Interestingly, short-chain maltooligosaccharides (DP 2 - 4) were significantly revealed at a higher level when r<jats:italic>Me</jats:italic>PUL was mixed with cassava isoamylase 3 (r<jats:italic>Me</jats:italic>ISA3), compared to that of each single enzyme reaction. This suggests that <jats:italic>Me</jats:italic>PUL and <jats:italic>Me</jats:italic>ISA3 debranch β-limit dextrin in a synergistic manner, which represents a major starch catabolising process in dicots. Additionally, subcellular localisation suggested the involvement of <jats:italic>Me</jats:italic>PUL in starch catabolism, which normally takes place in plastids.</jats:p>

<jats:p>Addressing the challenges of climate change and durum wheat production is becoming an important driver for food and nutrition security in the Mediterranean area, where are located the major producing countries (Italy, Spain, France, Greece, Morocco, Algeria, Tunisia, Turkey, and Syria). One of the emergent strategies, to cope with durum wheat adaptation, is the exploration and exploitation of the existing genetic variability in landrace populations. In this context, this review aims to highlight the important role of durum wheat landraces as a useful genetic resource to improve the sustainability of Mediterranean agroecosystems, with a focus on adaptation to environmental stresses. We described the most recent molecular techniques and statistical approaches suitable for the identification of beneficial genes/alleles related to the most important traits in landraces and the development of molecular markers for marker-assisted selection. Finally, we outline the state of the art about landraces genetic diversity and signature of selection, already identified from these accessions, for adaptability to the environment.</jats:p>

<jats:sec><jats:title>Introduction</jats:title><jats:p>Nondestructive detection of crop phenotypic traits in the field is very important for crop breeding. Ground-based mobile platforms equipped with sensors can efficiently and accurately obtain crop phenotypic traits. In this study, we propose a dynamic 3D data acquisition method in the field suitable for various crops by using a consumer-grade RGB-D camera installed on a ground-based movable platform, which can collect RGB images as well as depth images of crop canopy sequences dynamically.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>A scale-invariant feature transform (SIFT) operator was used to detect adjacent date frames acquired by the RGB-D camera to calculate the point cloud alignment coarse matching matrix and the displacement distance of adjacent images. The data frames used for point cloud matching were selected according to the calculated displacement distance. Then, the colored ICP (iterative closest point) algorithm was used to determine the fine matching matrix and generate point clouds of the crop row. The clustering method was applied to segment the point cloud of each plant from the crop row point cloud, and 3D phenotypic traits, including plant height, leaf area and projected area of individual plants, were measured.</jats:p></jats:sec><jats:sec><jats:title>Results and Discussion</jats:title><jats:p>We compared the effects of LIDAR and image-based 3D reconstruction methods, and experiments were carried out on corn, tobacco, cottons and Bletilla striata in the seedling stage. The results show that the measurements of the plant height (R²= 0.9~0.96, RSME = 0.015~0.023 m), leaf area (R²= 0.8~0.86, RSME = 0.0011~0.0041 <jats:italic>m</jats:italic><jats:sup>2</jats:sup> ) and projected area (R² = 0.96~0.99) have strong correlations with the manual measurement results. Additionally, 3D reconstruction results with different moving speeds and times throughout the day and in different scenes were also verified. The results show that the method can be applied to dynamic detection with a moving speed up to 0.6 m/s and can achieve acceptable detection results in the daytime, as well as at night. Thus, the proposed method can improve the efficiency of individual crop 3D point cloud data extraction with acceptable accuracy, which is a feasible solution for crop seedling 3D phenotyping outdoors.</jats:p></jats:sec>

<jats:sec><jats:title>Introduction</jats:title><jats:p>Net primary productivity (NPP) is an important indicator used to characterize the productivity of terrestrial ecosystems. The spatial distribution and dynamic change in NPP are closely related to regional climate, vegetation growth and human activities. Studying the spatiotemporal dynamics of NPP and its influencing factors plays a vital role in understanding ecosystem carbon sink capacity.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Based on MODIS-NPP data, meteorological data, and land use data from 2000 to 2020, we analyzed the spatiotemporal variation characteristics and influencing factors of NPP in the middle reaches of the Yellow River (MRYR) by using unary linear regression analysis, third-order partial correlation analysis, and Sen+Mann-Kendall trend analysis.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The results showed that the annual average NPP of the MRYR was 319.24 gCm<jats:sup>-2</jats:sup>a<jats:sup>-1</jats:sup> with a spatially decreasing trend from the southern part to the northern part. From 2000 to 2020, the annual average NPP experienced a fluctuating upward trend at a rate of 2.83 gCm<jats:sup>-2</jats:sup>a<jats:sup>-1</jats:sup>, and the area with a significant upward trend accounted for 87.68%. The NPP of different land use types differed greatly, in which forest had the greatest increase in NPP. Temperature had a negative correlation with NPP in most parts of the MRYR. Water vapor pressure promoted the accumulation of NPP in the northwestern MRYR. The areas with a positive correlation between NPP and water vapor pressure accounted for 87.6%, and 20.43% of the MRYR area passed the significance test of P&amp;lt; 0.05.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>The results of the study highlight the impact of climate factors and land-use changes on NPP and provide theoretical guidance for high-quality sustainable development in the MRYR.</jats:p></jats:sec>

<jats:p>Red color resulted from anthocyanin pigment, is an essential trait for premium table grape production. Anthocyanin biosynthesis occurs through the flavonoid pathway which includes several enzymatic reactions coded by different genes. The expression of these genes is regulated by different cultural practices, cultivars, environmental conditions, and plant hormones. Recently, we reported that the anthocyanin pathway is regulated by several factors such as light and antioxidant activity. Despite the advances in cultural practices, it is still challenging to produce table grapes with high coloration, especially under the current and expected global climate change in warmer areas such as California. In the current study, we deployed two approaches to improve the accumulation of red pigment in table grapes. The first approach involves improving the expression of critical genes involved in the anthocyanin pathway through hormonal treatments and light manipulation using a reflective ground cover (RGC). The second approach was to reduce the negative effect of heat stress through stimulation of the antioxidant pathway to help remove free radicals. Treatments included ethephon (ET) at 600 mg/L, silicon (Si) at 175 mg/L, and a commercial light-reflective white ground cover (RGC) alone and in various combinations. Treatments were conducted either with or without a combination of cluster-zone leaf removal at veraison (LR) on Flame seedless (<jats:italic>Vitis vinifera</jats:italic> L.). Data collected in 2019 and 2020 showed that the best treatment to improve berry coloration was using ET in combination with Si and RGC, applied at veraison. Adding the LR to this combination did not improve berry color any further, but rather caused a reduction in color development. RGC without conducting LR at veraison significantly increased the quantity of reflected blue and red lights as well as the red (R) to far-red (FR) ratio (R: FR) around clusters. Results were in accordance with the increase in gene expression of <jats:italic>flavonoid-3-O-glucosyltransferase</jats:italic> (<jats:italic>UFGT</jats:italic>), a key gene in the anthocyanin biosynthesis pathway, as well as <jats:italic>Peroxidase dismutase</jats:italic> (<jats:italic>POD</jats:italic>). Manipulating the light spectrum and application of silicon in combination with the ethephon treatment could be used in table grape vineyards to improve the ethylene-induced anthocyanin accumulation and coloration.</jats:p>

<jats:p>The regulation of intracellular pyrophosphate (PPi) level is crucial for proper morphogenesis across all taxonomic kingdoms. PPi is released as a byproduct from ~200 metabolic reactions, then hydrolyzed by either membrane-bound (H<jats:sup>+</jats:sup>-PPase) or soluble pyrophosphatases (PPases). In Arabidopsis, the loss of the vacuolar H<jats:sup>+</jats:sup>-PPase/FUGU5, a key enzyme in PPi homeostasis, results in delayed growth and a number of developmental defects, pointing to the importance of PPi homeostasis in plant morphogenesis. The Arabidopsis genome encodes several PPases in addition to FUGU5, such as PPsPase1/PECP2, VHP2;1 and VHP2;2, although their significance regarding PPi homeostasis remains elusive. Here, to assess their contribution, phenotypic analyses of cotyledon aspect ratio, palisade tissue cellular phenotypes, adaxial side pavement cell complexity, stomatal distribution, and etiolated seedling length were performed, provided that they were altered due to excess PPi in a <jats:italic>fugu5</jats:italic> mutant background. Overall, our analyses revealed that the above five traits were unaffected in <jats:italic>ppspase1/pecp2</jats:italic>, <jats:italic>vhp2;1</jats:italic> and <jats:italic>vhp2;2</jats:italic> loss-of-function mutants, as well as in <jats:italic>fugu5</jats:italic> mutant lines constitutively overexpressing <jats:italic>PPsPase1/PECP2</jats:italic>. Furthermore, metabolomics revealed that <jats:italic>ppspase1/pecp2</jats:italic>, <jats:italic>vhp2;1</jats:italic> and <jats:italic>vhp2;2</jats:italic> etiolated seedlings exhibited metabolic profiles comparable to the wild type. Together, these results indicate that the contribution of PPsPase1/PECP2, VHP2;1 and VHP2;2 to PPi levels is negligible in comparison to FUGU5 in the early stages of seedling development.</jats:p>