Genomic Analysis of the 1-Aminocyclopropane-1-Carboxylate Deaminase-Producing Pseudomonas thivervalensis SC5 Reveals Its Multifaceted Roles in Soil and in Beneficial Interactions With Plants

Beneficial 1-aminocyclopropane-1-carboxylate (ACC) deaminase-producing bacteria promote plant growth and stress resistance, constituting a sustainable alternative to the excessive use of chemicals in agriculture. In this work, the increased plant growth promotion activity of the ACC deaminase-producing Pseudomonas thivervalensis SC5, its ability to limit the growth of phytopathogens, and the genomics behind these important properties are described in detail. P. thivervalensis SC5 displayed several active plant growth promotion traits and significantly increased cucumber plant growth and resistance against salt stress (100mmol/L NaCl) under greenhouse conditions. Strain SC5 also limited the in vitro growth of the pathogens Botrytis cinerea and Pseudomonas syringae DC3000 indicating active biological control activities. Comprehensive analysis revealed that P. thivervalensis SC5 genome is rich in genetic elements involved in nutrient acquisition (N, P, S, and Fe); osmotic stress tolerance (e.g., glycine-betaine, trehalose, and ectoine biosynthesis); motility, chemotaxis and attachment to plant tissues; root exudate metabolism including the modulation of plant phenolics (e.g., hydroxycinnamic acids), lignin, and flavonoids (e.g., quercetin); resistance against plant defenses (e.g., reactive oxygens species-ROS); plant hormone modulation (e.g., ethylene, auxins, cytokinins, and salicylic acid), and bacterial and fungal phytopathogen antagonistic traits (e.g., 2,4-diacetylphloroglucinol, HCN, a fragin-like non ribosomal peptide, bacteriocins, a lantipeptide, and quorum-quenching activities), bringing detailed insights into the action of this versatile plant-growth-promoting bacterium. Ultimately, the combination of both increased plant growth promotion/protection and biological control abilities makes P. thivervalensis SC5 a prime candidate for its development as a biofertilizer/biostimulant/biocontrol product. The genomic analysis of this bacterium brings new insights into the functioning of Pseudomonas and their role in beneficial plant-microbe interactions.

Comparative Effects of Organic and Inorganic Manure on the Growth and Development of Cucumis Sativus

A study on the comparative effects of organic manure and inorganic fertilizer on the growth and development of Cucumis sativa was carried out at Nnamdi Azikwe University Awka. Randomized Complete Block Design was used for the study. 30kg of sandy loam soil was used and different concentrations of organic manure were 0.5kg, 1.0kg, 1.5kg and 2.0kg, while 0.3kg of inorganic manure was used to treat the soil. Growth parameters such as changes in length, girth, leaf area and the number of leaves were measured on weekly basis and recorded accordingly. The results on the effect of organic manure and inorganic manure on the leaf area of cucumber revealed that the 2kg of organic manure gave the highest leaf area increase of cucumber from 9.33±0.306cm2 in week 1 to 298.79±5.526cm2 in week 6. The performance of 2kg of organic manure is followed by 1.5kg of organic manure which gave leaf area increase of cucumber from 8.97±0.351cm2 in week 1 to 246.69±5.754 cm2 in week 6. The control increased the least leaf area from 3.20±0.200cm2in week 1 to 96.08±5.562 cm2in week 6. Analysis of variance showed a significant difference (p<0.05) in the leaf area of cucumber between treatments studied from week 1 to week 6. Also, results on the effect of organic manure and inorganic fertilizer on the height of cucumber revealed that the 2kg of organic manure gave the highest height increase of cucumber from 6.20±0.100 cm in week 1 to 99.60±0.200 cm in week 6. The performance of 2kg of organic manure is followed by inorganic manure which gave a height increase of cucumber from 5.33±0.058 cm in week 1 to 88.73±4.143 cm in week 6. The control gave the least height increase from 3.33±0.153 cm in week 1 to 29.20±1.153 cm in week 6. Analysis of variance showed a significant difference (p<0.05) in the height of cucumber between treatments studied (that is the different rates of organic manure, inorganic manure and control) from week 1 to week 6. study shows that the treatment of inorganic fertilizer on the cucumber plant had a significant impact on cucumber while organic manure alone gave the highest stem height and stem girth of cucumber.51

NATURAL INFECTION OF Tobacco mosaic virus ON BUTTERNUT SQUASH IN BALI, INDONESIA

Natural infection of Tobacco mosaic virus on butternut squash in Bali, Indonesia. Tobacco mosaic virus (TMV) was a newly emerging virus infecting cucumbers in Indonesia since 2017. The mosaic disease caused by TMV potentially caused yield loss cucumber in Java. In 2019, mosaic symptoms were observed in butternut squash plants in Bali and molecular detection using universal primer of Tobamovirus indicated the presence of TMV infection. Further research was conducted to determine molecular characteristics of TMV on butternut squash plants in Bali. Specific DNA bands of Tobamovirus were amplified using reverse transcription polymerase chain reaction method, followed by DNA sequencing. The DNA were successfully amplified from CP Tobamovirus using universal primers from several butternut squash samples, i.e. Denpasar, Gianyar, Buleleng, and Karangasem Districts. The homology analysis of nucleotide and amino acid sequences of TMV among isolates from Denpasar, Gianyar, Buleleng, and Karangasem Districts was ranged between 95.6 – 97.7% and 98.1 – 99.4%, respectively. This indicated that low genetic diversity of TMV among Bali isolates. The highest homology of corresponding sequences of TMV isolates from Denpasar, Gianyar, Buleleng, and Karangasem Districts was closely related to TMV Kediri-Indonesia isolate on cucumber plant. Correspondingly, the phylogenetic analysis showed that TMV Bali isolates were categorized into same cluster with Kediri-Indonesia isolates. This was the first report of TMV on butternut squash in Indonesia.

Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation Systems Using Biostimulators

Cultivation of cucumber in greenhouses is predominantly carried out in soilless cultivation systems mainly in substrate culture. The use of organic and completely compostable substrates is of rising interest in such systems, unclean sheep wool was formed as substrate slabs, peat slabs and coconut fiber slabs were compared with mineral substrates rockwool and perlite. In general can be stated, intensively in greenhouses cultivated crops such as cucumbers, suffer often from inadequate abiotic or biotic growth conditions in particular in the rhizosphere. Many studies were done to find growth promoters or biostimulators to stabilize the growing condition in the rhizosphere, in case of stress situation as fluctuating salt concentration EC and pH value, but also in case of temperature stress. K-Humate, Lactate and Bacillus subtilis were investigated as biostimulators in such situations. Different concentration and combination of these biostimulators were investigated but also the methods of application on leaves and roots respectively. Very successful was used for the stabilization of the EC value for cucumber plants growing in substrate the application of K-Humate and B. subtilis (FZB24®) as single component and combined. Following the results, it can be assumed, the application of the combined biostimulators with all substances if applied over the roots was a stimulating effect visible, whereas if applied over the leaves an inhibiting effect for cucumber plant growth. Application of the biostimulators solution with all three components BS-FZB24® (0.2%), K-Humate (0.01%), and LACTOFOL “O” (0.1%) were tested regarding their effects in case of strong but short time pH and temperature stress the growth of cucumber plants. There are a strong correlation between green biomass of treated cucumber plants and their root mass. It can be assumed that one of the effects of stress prevention through the biostimulators is primarily based on increasing root growth.

Application of Various Extracts Enhances the Growth and Yield of Cucumber (Cucumis sativus L.) without Compromising the Biochemical Content

This study examined the effects of changes to application methods, application time, and combinations of different extracts on the growth and yield of cucumbers. Chlorophyll and photosynthetic efficiency levels in cucumber plants were also measured after receiving treatments of selected liquid fertilizers. Mineral nutrition levels in both extracts themselves and the test plants were measured. Crude protein, crude fat, ash, total phenol and flavonoid contents, and DPPH radical scavenging activity in cucumber were determined. Cucumber plant height and shoot fresh weight at 7 and 14 days after treatments generally increased significantly regardless of the extraction methods or extract materials. On the other hand, cucumber leaf number was similar regardless of the extracts used. The application frequency effects differed according to the extraction methods, extracts, and parameters investigated. In addition, the combinations of extracts did not produce significant increases in cucumber plant growth. Cucumber fruit weight was 17–81%, 10–61%, and 10–45% higher than the control or oil cake when the plants were treated with fermentation, boiled water, and water extracts, respectively. The chlorophyll content and photosynthetic efficiency of cucumber plants treated with various extracts did not vary significantly. Extracts with the highest mineral nutrients were not effective growth promotors of cucumber plants. This means that growth promotion may not be caused by high levels of one specific macro or micro element but by some specific combinations of various elements. Compared to the control, most elements in the cucumber leaves decreased significantly when treated with most of the extracts. Generally, crude protein, crude fat, and ash contents were not negatively affected by the extract treatments. Moreover, most of the extracts did not adversely affect total phenol and flavonoid contents and DPPH radical scavenging activity. Thus, these extracts may be used for growth promotion without negative effects to primary and secondary substances in organically cultivated crop fields.

Characteristics and expression patterns of six α-galactosidases in cucumber (Cucumis sativus L.)

Six putative α-galactosidase genes (α-Gals), three acid forms (CsGAL1, CsGAL2, CsGAL3) and three alkaline forms (CsAGA1, CsAGA2, CsAGAL3), were found in the cucumber genome. It is interesting to know the expression pattern and possible function of these α-Gals in the cucumber plant since it is a stachyose-translocating species. In this study, full-length cDNAs of six α-Gals were cloned and heterologously expressed. The result showed that all recombinant proteins revealed acid or alkaline α-Gal activities with different substrate specificities and pH or temperature responding curves, indicating their distinct roles in cucumber plants. Phylogenetic analysis of collected α-Gal amino acid sequences from different plants indicated that the ancestor of both acid and alkaline α-Gals existed before monocots and dicots separated. Generally, six α-Gal genes are universally expressed in different cucumber organs. CsGAL2 highly expressed in fasting-growing leaves, fruits and germinating seeds; CsGAL3 mainly distributes in vacuoles and significantly expressed in cucumber fruits, senescent leaves and seeds during late stage germination; The expression of CsAGA1 increased from leaf 1 to leaf 3 (sink leaves) and then declined from leaf 4 to leaf 7 (source leaves), and this isoform also highly expressed in male flowers and germinating seeds at early stage; CsAGA2 significantly expressed in cucumber leaves and female flowers; CsAGA3 is localized in plastids and also actively expressed in senescent leaves and germinating seeds; The role of CsGAL1 in cucumber plants is now unclear since its expression was relatively low in all organs. According to their expression patterns, subcellular localizations and previously reported functions of these isoforms in other plants, combining the data of soluble sugars contents in different tissues, the possible functions of these α-Gals were discussed.

Kigelia africana (Lam.) Benth: Sausage of Medicinal Properties

Nature had been serving humanity from ages by providing with the food and resources of our well-being. It was serving with medicines and herbs that are used to heal many disorders. There were numerous lead molecules that had been isolated from natural sources, especially plants. Kigelia africana (Lam.) Benth is a widely distributed plant in Africa. Savage tree or the cucumber plant is the common name of the plant. It belongs to the family Bignoniaceae. The plant is a native plant of Africa which is confined to the south, central and West African regions. Preliminary phytochemical screening was performed for the plant revealed the presence of alkaloids, tannins, saponins, flavonoids, carbohydrates and sapogenetic glycosides. The plant has been reported to contain flavonoids, aldehyde iridioids, coumarins like dihydroisocoumarin, naphthoquinones like pinnatal, isopnnatal, kigelinole and isokigelinole. It had been investigated and proven to possess various chemicals that treat inflammations, cancers, psoriasis, dysentery and bacterial infections.