Catálogo de publicaciones - revistas

<jats:p>Soluble sugars are an important determinant of fruit taste, but their accumulation mechanisms remain elusive. In this study, we report two vacuolar invertase inhibitor genes involved in sugar accumulation in peach, <jats:italic>PpINHa</jats:italic> and <jats:italic>PpINH3</jats:italic>. Transient overexpression of <jats:italic>PpINH3</jats:italic> in peach fruits resulted in an increase in sugar content, while the opposite trend was detected for <jats:italic>PpINHa</jats:italic>. Unexpectedly, PpINH3 and PpINHa both had no physical interaction with vacuolar invertase (VIN). Moreover, the <jats:italic>PpVIN</jats:italic> genes had no or extremely low expression in fruits at the ripening stage. These results suggested that the regulatory role of PpINHa and PpINH3 in sugar accumulation is unlikely due to their interaction with PpVINs. Additionally, overexpression of <jats:italic>PpINHa</jats:italic> and <jats:italic>PpINH3</jats:italic> had an impact on transcription of genes related to fruit sugar metabolism and transport, which is likely responsible for their regulatory role in fruit sugar accumulation. Altogether, these results indicated an important role of <jats:italic>PpINHs</jats:italic> in fruit accumulation in peach. Our study provides new insights into molecular mechanisms underlying sugar accumulation, which could be useful for genetic improvement of fruit taste in breeding programs of peach and other fruit crops.</jats:p>

<jats:p>The distribution of elite soybean (<jats:italic>Glycine max</jats:italic>) cultivars is limited due to their highly sensitive to photoperiod, which affects the flowering time and plant architecture. The recent emergence of CRISPR/Cas9 technology has uncovered new opportunities for genetic manipulation of soybean. The major maturity gene <jats:italic>E1</jats:italic> of soybean plays a critical role in soybean photoperiod response. Here, we performed CRISPR/Cas9-mediated targeted mutation of <jats:italic>E1</jats:italic> gene in soybean cultivar Tianlong1 carrying the dominant <jats:italic>E1</jats:italic> to investigate its precise function in photoperiod regulation, especially in plant architecture regulation. Four types of mutations in the <jats:italic>E1</jats:italic> coding region were generated. No off-target effects were observed, and homozygous trans-clean mutants without T-DNA were obtained. The photoperiod sensitivity of <jats:italic>e1</jats:italic> mutants decreased relative to the wild type plants; however, <jats:italic>e1</jats:italic> mutants still responded to photoperiod. Further analysis revealed that the homologs of <jats:italic>E1</jats:italic>, <jats:italic>E1</jats:italic>-<jats:italic>La</jats:italic>, and <jats:italic>E1</jats:italic>-<jats:italic>Lb</jats:italic>, were up-regulated in the <jats:italic>e1</jats:italic> mutants, indicating a genetic compensation response of <jats:italic>E1</jats:italic> and its homologs. The <jats:italic>e1</jats:italic> mutants exhibited significant changes in the architecture, including initiation of terminal flowering, formation of determinate stems, and decreased branch numbers. To identify <jats:italic>E1</jats:italic>-regulated genes related to plant architecture, transcriptome deep sequencing (RNA-seq) was used to compare the gene expression profiles in the stem tip of the wild-type soybean cultivar and the <jats:italic>e1</jats:italic> mutants. The expression of shoot identity gene <jats:italic>Dt1</jats:italic> was significantly decreased, while <jats:italic>Dt2</jats:italic> was significantly upregulated. Also, a set of MADS-box genes was up-regulated in the stem tip of <jats:italic>e1</jats:italic> mutants which might contribute to the determinate stem growth habit.</jats:p>

<jats:p>Rice is a key crop for meeting the global food demand and ensuring food security. However, the crop has been facing great problems to combat the weed problem. Synthetic herbicides pose a severe threat to the long-term viability of agricultural output, agroecosystems, and human health. Allelochemicals, secondary metabolites of allelopathic plants, are a powerful tool for biological and eco-friendly weed management. The dynamics of weed species in various situations are determined by crop allelopathy. Phenolics and momilactones are the most common allelochemicals responsible for herbicidal effects in rice. The dispersion of allelochemicals is influenced not only by crop variety but also by climatic conditions. The most volatile chemicals, such as terpenoids, are usually emitted by crop plants in drought-stricken areas whereas the plants in humid zones release phytotoxins that are hydrophilic in nature, including phenolics, flavonoids, and alkaloids. The allelochemicals can disrupt the biochemical and physiological processes in weeds causing them to die finally. This study insight into the concepts of allelopathy and allelochemicals, types of allelochemicals, techniques of investigating allelopathic potential in rice, modes of action of allelochemicals, pathways of allelochemical production in plants, biosynthesis of allelochemicals in rice, factors influencing the production of allelochemicals in plants, genetical manipulation through breeding to develop allelopathic traits in rice, the significance of rice allelopathy in sustainable agriculture, etc. Understanding these biological phenomena may thus aid in the development of new and novel weed-control tactics while allowing farmers to manage weeds in an environmentally friendly manner.</jats:p>

<jats:p>Increasing the water use efficiency of crops is an important agricultural goal closely related to the root system —the primary plant organ for water and nutrient acquisition. In an attempt to evaluate the response of root growth and development of soybean to water supply levels, 200 genotypes were grown in a sandy field for 3 years under irrigated and non-irrigated conditions, and 14 root traits together with shoot fresh weight and plant height were investigated. Three-way ANOVA revealed a significant effect of treatments and years on growth of plants, accounting for more than 80% of the total variability. The response of roots to irrigation was consistent over the years as most root traits were improved by irrigation. However, the actual values varied between years because the growth of plants was largely affected by the field microclimatic conditions (i.e., temperature, sunshine duration, and precipitation). Therefore, the best linear unbiased prediction values for each trait were calculated using the original data. Principal component analysis showed that most traits contributed to principal component (PC) 1, whereas average diameter, the ratio of thin and medium thickness root length to total root length contributed to PC2. Subsequently, we focused on selecting genotypes that exhibited significant improvements in root traits under irrigation than under non-irrigated conditions using the increment (I-index) and relative increment (RI-index) indices calculated for all traits. Finally, we screened for genotypes with high stability and root growth over the 3 years using the multi-trait selection index (MTSI).Six genotypes namely, GmJMC130, GmWMC178, GmJMC092, GmJMC068, GmWMC075, and GmJMC081 from the top 10% of genotypes scoring MTSI less than the selection threshold of 7.04 and 4.11 under irrigated and non-irrigated conditions, respectively, were selected. The selected genotypes have great potential for breeding cultivars with improved water usage abilities, meeting the goal of water-saving agriculture.</jats:p>

<jats:p>A new species, <jats:italic>Allium sulaimanicum</jats:italic>, is described from northern Balochistan and southern Khyber Pakhtunkhwa in Pakistan based on morphological, molecular, and cytological studies. The new species is characterised by long runner-like cylindrical rhizomes of adult plants, cylindrical bulbs, linear leaves with minute soft hairs along veins, campanulate perigonium, and white to creamy white, ovate to elliptical, 4.5–5-mm-long acute tepals, with brownish to purplish nerves, stamens as long as to slightly longer than tepals, yellow to brick red anthers, hexagonal ovary, and white and papillate/warty along angles. The presence of long herbaceous rhizomes indicated serious isolation of the new species; hence, a new section <jats:italic>Sulaimanicum</jats:italic> is proposed to accommodate the new species. The new species is diploid with a chromosome number of 2n = 16. Detailed morphological description, illustrations, phylogenetic analyses based on sequences of plastid spacers (<jats:italic>rpl</jats:italic>32-<jats:italic>trn</jats:italic>L (UAG) and <jats:italic>trn</jats:italic>Q-<jats:italic>rps</jats:italic>16) and nuclear ITS, karyotype features, and a distribution map of the new species are provided.</jats:p>

<jats:p>Uniconazole, a triazole plant growth regulator, is widely used to regulate plant height and prevent the overgrowth of seedlings. However, the underlying molecular mechanism of uniconazole in inhibiting the hypocotyl elongation of seedlings is still largely unclear, and there has been little research on the integration of transcriptomic and metabolomic data to investigate the mechanisms of hypocotyl elonga-tion. Herein we observed that the hypocotyl elongation of flowering Chinese cabbage seedings was significantly inhibited by uniconazole. Interestingly, based on combined transcriptome and metabolome analyses, we found that the “phenylpropanoid biosynthesis” pathway was significantly affected by uniconazole. In this pathway, only one member of the portal enzyme gene family, named <jats:italic>BrPAL4</jats:italic>, was remarkably downregulated, which was related to lignin biosynthesis. Furthermore, the yeast one-hybrid and dual-luciferase assays showed that BrbZIP39 could directly bind to the promoter region of <jats:italic>BrPAL4</jats:italic> and activate its transcript. The virus-induced gene silencing system further demonstrated that <jats:italic>BrbZIP39</jats:italic> could positively regulate hypocotyl elongation and the lignin biosynthesis of hypocotyl. Our findings provide a novel insight into the molecular regulatory mechanism of uniconazole inhibiting hypocotyl elongation in flowering Chinese cabbage and confirm, for the first time, that uniconazole decreases lignin content through repressing the BrbZIP39–<jats:italic>BrPAL4</jats:italic> module-mediated phenylpropanoid biosynthesis, which leads to the hypocotyl dwarfing of flowering Chinese cabbage seedlings.</jats:p>

<jats:p>Cystathionine beta synthase (CBS) domains containing proteins (CDCPs) plays an important role in plant development through regulation of the thioredoxin system, as well as its ability to respond to biotic and abiotic stress conditions. Despite this, no systematic study has examined the wheat CBS gene family and its relation to high temperature-induced male sterility. In this study, 66 CBS family members were identified in the wheat genome, and their gene or protein sequences were used for subsequent analysis. The <jats:italic>TaCBS</jats:italic> gene family was found to be unevenly distributed on 21 chromosomes, and they were classified into four subgroups according to their gene structure and phylogeny. The results of collinearity analysis showed that there were 25 shared orthologous genes between wheat, rice and <jats:italic>Brachypodium distachyon</jats:italic>, and one shared orthologous gene between wheat, millet and barley. The cis-regulatory elements of the <jats:italic>TaCBS</jats:italic> were related to JA, IAA, MYB, etc. GO and KEGG pathway analysis identified these <jats:italic>TaCBS</jats:italic> genes to be associated with pollination, reproduction, and signaling and cellular processes, respectively. A heatmap of wheat plants based on transcriptome data showed that <jats:italic>TaCBS</jats:italic> genes were expressed to a higher extent in spikelets relative to other tissues. In addition, 29 putative tae-miRNAs were identified, targeting 41 <jats:italic>TaCBS</jats:italic> genes. Moreover, qRT-PCR validation of six <jats:italic>TaCBS</jats:italic> genes indicated their critical role in anther development, as five of them were expressed at lower levels in heat-stressed male sterile anthers than in Normal anthers. Together with anther phenotypes, paraffin sections, starch potassium iodide staining, and qRT-PCR data, we hypothesized that the <jats:italic>TaCBS</jats:italic> gene has a very important connection with the heat-stressed sterility process in wheat, and these data provide a basis for further insight into their relationship.</jats:p>

<jats:p>The <jats:italic>Arabidopsis</jats:italic> DEMETER (DME) DNA glycosylase demethylates the central cell genome prior to fertilization. This epigenetic reconfiguration of the female gamete companion cell establishes gene imprinting in the endosperm and is essential for seed viability. DME demethylates small and genic-flanking transposons as well as intergenic and heterochromatin sequences, but how DME is recruited to these loci remains unknown. H1.2 was identified as a DME-interacting protein in a yeast two-hybrid screen, and maternal genome H1 loss affects DNA methylation and expression of selected imprinted genes in the endosperm. Yet, the extent to which H1 influences DME demethylation and gene imprinting in the <jats:italic>Arabidopsis</jats:italic> endosperm has not been investigated. Here, we showed that without the maternal linker histones, DME-mediated demethylation is facilitated, particularly in the heterochromatin regions, indicating that H1-bound heterochromatins are barriers for DME demethylation. Loss of H1 in the maternal genome has a very limited effect on gene transcription or gene imprinting regulation in the endosperm; however, it variably influences euchromatin TE methylation and causes a slight hypermethylation and a reduced expression in selected imprinted genes. We conclude that loss of maternal H1 indirectly influences DME-mediated demethylation and endosperm DNA methylation landscape but does not appear to affect endosperm gene transcription and overall imprinting regulation.</jats:p>

<jats:sec><jats:title>Introduction</jats:title><jats:p>Protein kinases play an important role in plants in response to environmental changes through signal transduction. As a large family of protein kinases, sucrose non-fermenting-1 (SNF1)-related kinases (SnRKs) were found and functionally verified in many plants. Nevertheless, little is known about the <jats:italic>SnRK</jats:italic> family of <jats:italic>Zea mays</jats:italic>.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Evolutionary relationships, chromosome locations, gene structures, conserved motifs, and cis-elements in promoter regions were systematically analyzed. Besides, tissue-specific and stress-induced expression patterns of <jats:italic>ZmSnRKs</jats:italic> were determined. Finally, functional regulatory networks between <jats:italic>ZmSnRKs</jats:italic> and other proteins or miRNAs were constructed.</jats:p></jats:sec><jats:sec><jats:title>Results and Discussion</jats:title><jats:p>In total, 60 <jats:italic>SnRK</jats:italic> genes located on 10 chromosomes were discovered in maize. <jats:italic>ZmSnRKs</jats:italic> were classified into three subfamilies (<jats:italic>ZmSnRK1</jats:italic>, <jats:italic>ZmSnRK2</jats:italic>, and <jats:italic>ZmSnRK3</jats:italic>), consisting of 4, 14, and 42 genes, respectively. Gene structure analysis showed that 33 of the 42 <jats:italic>ZmSnRK3</jats:italic> genes contained only one exon. Most <jats:italic>ZmSnRK</jats:italic> genes contained at least one ABRE, MBS, and LTR cis-element and a few <jats:italic>ZmSnRK</jats:italic> genes had AuxRR-core, P-box, MBSI, and SARE ciselements in their promoter regions. The Ka:Ks ratio of 22 paralogous <jats:italic>ZmSnRK</jats:italic> gene pairs revealed that the <jats:italic>ZmSnRK</jats:italic> gene family had experienced a purifying selection. Meanwhile, we analyzed the expression profiles of <jats:italic>ZmSnRKs</jats:italic>, and they exhibited significant differences in various tissues and abiotic stresses. In addition, A total of eight ZmPP2Cs, which can interact with <jats:italic>ZmSnRK</jats:italic> proteins, and 46 miRNAs, which can target 24 <jats:italic>ZmSnRKs</jats:italic>, were identified. Generally, these results provide valuable information for further function verification of <jats:italic>ZmSnRKs</jats:italic>, and improve our understanding of the role of <jats:italic>ZmSnRKs</jats:italic> in the climate resilience of maize.</jats:p></jats:sec>

<jats:p>Evolutionary dynamics of AP2/ERF and WRKY genes, the major components of defense response were studied extensively in the sesame pan-genome. Massive variation was observed for gene copy numbers, genome location, domain structure, exon-intron structure and protein parameters. In the pan-genome, 63% of AP2/ERF members were devoid of introns whereas &amp;gt;99% of WRKY genes contained multiple introns. AP2 subfamily was found to be micro-exon rich with the adjoining intronic sequences sharing sequence similarity to many stress-responsive and fatty acid metabolism genes. WRKY family included extensive multi-domain gene fusions where the additional domains significantly enhanced gene and exonic sizes as well as gene copy numbers. The fusion genes were found to have roles in acquired immunity, stress response, cell and membrane integrity as well as ROS signaling. The individual genomes shared extensive synteny and collinearity although ecological adaptation was evident among the Chinese and Indian accessions. Significant positive selection effects were noticed for both micro-exon and multi-domain genes. Splice variants with changes in acceptor, donor and branch sites were common and 6-7 splice variants were detected per gene. The study ascertained vital roles of lipid metabolism and chlorophyll biosynthesis in the defense response and stress signaling pathways. 60% of the studied genes localized in the nucleus while 20% preferred chloroplast. Unique cis-element distribution was noticed in the upstream promoter region with MYB and STRE in WRKY genes while MYC was present in the AP2/ERF genes. Intron-less genes exhibited great diversity in the promoter sequences wherein the predominance of dosage effect indicated variable gene expression levels. Mimicking the NBS-LRR genes, a chloroplast localized WRKY gene, Swetha_24868, with additional domains of chorismate mutase, cAMP and voltage-dependent potassium channel was found to act as a master regulator of defense signaling, triggering immunity and reducing ROS levels.</jats:p>