Proteome evaluation of homolog abundance patterns in Arachis hypogaea cv. Tifrunner

Background Cultivated peanut (Arachis hypogaea, AABB genome), an allotetraploid from a cross between A. duranensis (AA genome) and A. ipaensis (BB genome), is an important oil and protein crop with released genome and RNA-seq sequence datasets. These datasets provide the molecular foundation for studying gene expression and evolutionary patterns. However, there are no reports on the proteomic data of A. hypogaea cv. Tifrunner, which limits understanding of its gene function and protein level evolution. Results This study sequenced the A. hypogaea cv. Tifrunner leaf and root proteome using the tandem mass tag technology. A total of 4803 abundant proteins were identified. The 364 differentially abundant proteins were estimated by comparing protein abundances between leaf and root proteomes. The differentially abundant proteins enriched the photosystem process. The number of biased abundant homeologs between the two sub-genomes A (87 homeologs in leaf and root) and B (69 and 68 homeologs in leaf and root, respectively) was not significantly different. However, homeologous proteins with biased abundances in different sub-genomes enriched different biological processes. In the leaf, homeologs biased to sub-genome A enriched biosynthetic and metabolic process, while homeologs biased to sub-genome B enriched iron ion homeostasis process. In the root, homeologs with biased abundance in sub-genome A enriched inorganic biosynthesis and metabolism process, while homeologs with biased abundance in sub-genome B enriched organic biosynthesis and metabolism process. Purifying selection mainly acted on paralogs and homeologs. The selective pressure values were negatively correlated with paralogous protein abundance. About 77.42% (24/31) homeologous and 80% (48/60) paralogous protein pairs had asymmetric abundance, and several protein pairs had conserved abundances in the leaf and root tissues. Conclusions This study sequenced the proteome of A. hypogaea cv. Tifrunner using the leaf and root tissues. Differentially abundant proteins were identified, and revealed functions. Paralog abundance divergence and homeolog bias abundance was elucidated. These results indicate that divergent abundance caused retention of homologs in A. hypogaea cv. Tifrunner.

Improved detection of Little cherry virus-2 using a hydrolysis probe to manage the Pacific Northwest little cherry disease epidemic.

Little cherry virus-2 (LChV-2) is a viral pathogen that is reaching epidemic levels in Washington state. This virus is insect-vectored and has significant impacts on sweet cherry production. To aid growers in making informed management decisions we sought to develop a diagnostic assay to better detect isolates of LChV-2 currently found in Washington, allowing for more accurate estimations of disease occurrence. This study showed that there were two distinct genotypes of LChV-2 present in Washington state. This information was used to develop an up-to-date reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) assay, which was then optimized, validated, and compared to four previously published assays using a panel of field samples. This comparison demonstrated that the newly developed assay provided greater sensitivity, accurately detecting less than 10 copies per reaction and could detect both LChV-2 genotypes. Finally, we examined the effect of potential inhibitors in various tissue types from cherry, finding that young leaf tissue affected sensitivity of detection less than root tissues.

Comparative plant biochemistry and soil biology of wild and cultivated cotton species

Purpose No attempts were made to analyze the diversity in soil and plant biology of wild cotton species (WCS) and cultivated cotton species (CCS), so far. Our study aimed to understand the differences in soil biological, plant biochemistry, and defense enzyme activities among the ten WCS and four CCS. Methods We studied the differences in soil biology, plant biochemistry, and defense enzyme activities among the ten WCS (Gossypium anomalum, G. aridum, G. australe, G. barbosanum, G. capitis-virides, G. davidsonii, G. raimondii, G. somalense, G. stocksii, G. thurberi) and four CCS (G. arboreum, G. herbaceum, G. hirsutum, and G. barbadense). Results CCS had 11%, 2%, and 10% higher soil respiration rate, microbial biomass carbon, and microbial metabolic quotient, respectively, compared to WCS. While, WCS had 45%, 15%, and 5% higher glomalin, soil polysaccharide, proteins, respectively, compared to CCS. WCS had 45%, 13%, 8%, and 13% higher acid and alkaline phosphatase, β-glucosidase, and soil dehydrogenase activities, respectively, compared to CCS. WCS had higher carbohydrates in the shoot (40%) and root (27%), while, CCS recorded higher proteins in the shoot (13%) and root (13%). WCS had significantly higher polyphenol oxidase (4% and 15%), peroxidase (30% and 31%), and catalase (36% and 31%) activities in shoots and root tissues, respectively, compared with CCS, while, WCS had higher phenol concentrations (4%) than CCS. Conclusion Our study suggests that the difference in soil biological, plant biochemistry, and defense enzyme activities among the WCS and CCS can be attributed to the inherent genetic makeup, which influences consequent plant and soil attributes.

Variation in Fungal Community in Grapevine (Vitis vinifera) Nursery Stock Depends on Nursery, Variety and Rootstock

Grapevine trunk diseases (GTDs) are caused by cryptic complexes of fungal pathogens and have become a growing problem for new grapevine (Vitis vinifera) plantations. We studied the role of the nursery, variety, and rootstock in the composition of the fungal communities in root collars and graft unions of planting material in Catalonia (NE Spain). We compared necrosis and fungal communities in graft unions and root collars at harvest, and then after three months of cold storage. We evaluated combinations of eleven red and five white varieties with four common rootstocks coming from six nurseries. Fungal communities were characterized by isolation and metabarcoding of the ITS2 region. Our data suggests that nursery followed by rootstock and variety had significant effects on necrosis and fungal community structure in graft and root tissues. Within the plant, we found large differences in terms fungal community distribution between graft and root tissues. Graft unions housed a significantly higher relative abundance of GTD-related Operational Taxonomic Units (OTUs) than root collars. More severe necrosis was correlated with a lower relative abundance of GTD-related OTUs based on isolation and metabarcoding analyses. Our results suggest that nurseries and therefore their plant production practices play a major role in determining the fungal and GTD-related fungal community in grapevine plants sold for planting. GTD variation across rootstocks and varieties could be explored as a venue for minimizing pathogen load in young plantations.

Isolation and characterization of a gene encoding farnesyl diphosphate synthase from \(\textit{Panax vietnamensis}\) Ha et Grushv

Panax vietnamensis Ha et Grushv. is a species of the genus Panax native to Central Vietnam, containing a family of triterpene saponins named ginsenosides. This group of biomolecules possesses valuable therapeutic properties against cancer, hepatitis, diabetes, inflammation as well as stress and anxiety. Farnesyl diphosphate synthase (FPS) is a key enzyme participating in the ginsenoside biosynthesis pathway. In this study, a FPS gene from P. vietnamensis (PvFPS) was isolated and characterized. The PvFPS cDNA contained an open reading frame of 1032 bp, encoding a polypeptide chain of 342 amino acid residues. Nucleotide sequence comparison showed that FPS was highly conserved among most species, with two Aspartate-rich motifs responsible for product chain length determination strongly sustained. PvFPS was closely related to those of the same genera and order and differed from those from other kingdoms. PvFPS expression was detected at a greater level in root tissues than in leaves in all ages. Our findings provided information concerning the properties of a crucial gene in the ginsenoside biosynthesis, thus enhancing our understanding of this important pathway.

TaLBD1, a LOB Transcription Factor Gene In T. Aestivum, Improves Plant N Starvation Adaptation Via Modulating N Acquisition-Associated Processes

Members of transcription factor (TF) families contribute largely to plant N starvation tolerance by regulating downstream stress defensive genes. In this study, we characterized TaLBD1, a Lateral Organ Boundary (LOB) TF gene in T. aestivum, in regulating plant low-N stress adaptation. TaLBD1 harbors the conserved domains specified by plant LOB proteins, targeting onto nucleus after endoplasmic reticulum (ER) assortment. The TaLBD1 transcripts were response sensitively to N starvation (NS) signaling, showing to be gradually upregulated in aerial and root tissues over a 27-h NS condition. The N. tabacum lines overexpressing TaLBD1 improved phenotype, root system architecture (RSA) establishment, biomass, and N contents of plants under NS treatment. The nitrate transporter gene NtNRT2.4 and PIN-FORMED gene NtPIN6 significantly upregulated in expression in NS-challenged lines; knockdown expression of NtNRT2.4 decreased N uptake and that of NtPIN6 alleviated RSA establishment relative to WT. These results validate the function of NRT and PIN genes in regulating plant N uptake and RSA behavior. RNA-seq analyses revealed that a quantity of genes modify expression in N-deprived lines overexpressing TaLBD1, which enriched into functional groups of signal transduction, transcription, protein biosynthesis, primary or secondary metabolism, and stress defensiveness. These findings suggested that the TaLBD1-improved NS adaptation attributes largely to its role in transcriptionally regulating NRT and PIN genes as well as in modulating those functional in various biological processes. TaLBD1 is a crucial regulator in plant N starvation tolerance and valuable target for molecular breeding high N use efficiency (NUE) crop cultivars.

Biocontrol Potential of Endophytic Actinobacteria against Fusarium solani, the Causal Agent of Sudden Decline Syndrome on Date Palm in the UAE

Thirty-one endophytic streptomycete and non-streptomycete actinobacteria were isolated from healthy date palm root tissues. In vitro screening revealed that the antifungal action of isolate #16 was associated with the production of cell-wall degrading enzymes, whereas with diffusible antifungal metabolites in isolate #28, albeit their production of volatile antifungal compounds. According to the 16S rRNA gene sequencing, isolates #16 and #28 were identified as Streptomyces polychromogenes UAE2 (Sp; GenBank Accession #: OK560620) and Streptomyces coeruleoprunus UAE1 (Sc; OK560621), respectively. The two antagonists were recovered from root tissues until 12 weeks after inoculation, efficiently colonized root cortex and xylem vessels, indicating that the date palm roots are a suitable habitat for these endophytic isolates. At the end of the greenhouse experiments, the development of sudden decline syndrome (SDS) was markedly suppressed by 53% with the application of Sp and 86% with Sc, confirming their potential in disease management. Results showed that the estimated disease severity indices in diseased seedlings were significantly (p < 0.05) reduced from 4.75 (scale of 5) to 2.25 or 0.67 by either Sp or Sc, respectively. In addition, conidial numbers of the pathogen significantly (p < 0.05) dropped by 38% and 76% with Sp and Sc, respectively, compared to infected seedlings with F. solani (control). Thus, the suppression of disease symptoms was superior in seedlings pre-inoculated with S. coeruleoprunus, indicating that the diffusible antifungal metabolites were responsible for F. solani retardation in these plants. This is the first report of actinobacteria naturally existing in date palm tissues acting as microbial antagonists against SDS on date palm.

Effects of Se Application on Polyamines and Carbon–Nitrogen Metabolism of Pepper Plants Suffering from Cd Toxicity

Previous studies have shown that the application of selenium (Se) can efficiently mitigate the toxic effects of cadmium (Cd) on various crops. The objective of the present work is to decipher the mechanisms responsible for the efficiency of Se against the effects of Cd in pepper plants, with respect to the carbon and nitrogen metabolism. The following were analyzed: the concentrations of anions related with this metabolism, such as nitrates, nitrites, and ammonium, the activities of different enzymes such as nitrate reductase, nitrite reductase, and glutamate synthase, polyamines in their different forms, organic acid salts, amino acids, and sugars in the leaf and root tissues of the pepper plants grown in a hydroponics system. Four different treatments were applied: plants without Cd or Se applied (−Cd/−Se); plants grown with Cd added to the nutrient solution (NS) but without Se (+Cd/−Se); plants grown with Cd in the NS, and with the foliar application of Se (+CD/+SeF); and lastly, plants grown with Cd in the NS, and with Se applied to the root (+Cd/+SeR). The metabolites and enzymes related with carbon and nitrogen metabolism were analyzed 15 days after the application. The results showed the superiority of the +Cd/+SeR treatment with respect to the +Cd/+SeF treatment, as shown by an increase in the conjugated polyamines, the decrease in glutamate and phenylalanine, and the increase of malate and chlorogenic acid. The results indicated that SeR decreased the accumulation and toxicity of Se as polyamine homeostasis improved, defense mechanisms such as the phenylpropanoid increased, and the entry of Cd into the plants was blocked.

De novo transcriptome and tissue specific expression analysis of genes associated with biosynthesis of secondary metabolites in Operculina turpethum (L.)

This study reported the first-ever de novo transcriptome analysis of Operculina turpethum, a high valued endangered medicinal plant, using the Illumina HiSeq 2500 platform. The de novo assembly generated a total of 64,259 unigenes and 20,870 CDS (coding sequence) with a mean length of 449 bp and 571 bp respectively. Further, 20,218 and 16,458 unigenes showed significant similarity with identified proteins of NR (non-redundant) and UniProt database respectively. The homology search carried out against publicly available database found the best match with Ipomoea nil sequences (82.6%). The KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis identified 6538 unigenes functionally assigned to 378 modules with phenylpropanoid biosynthesis pathway as the most enriched among the secondary metabolite biosynthesis pathway followed by terpenoid biosynthesis. A total of 17,444 DEGs were identified among which majority of the DEGs (Differentially Expressed Gene) involved in secondary metabolite biosynthesis were found to be significantly upregulated in stem as compared to root tissues. The qRT-PCR validation of 9 unigenes involved in phenylpropanoid and terpenoid biosynthesis also showed a similar expression pattern. This finding suggests that stem tissues, rather than root tissues, could be used to prevent uprooting of O. turpethum in the wild, paving the way for the plant's effective conservation. Moreover, the study formed a valuable repository of genetic information which will provide a baseline for further molecular research.