Bitter Melon ( L.) Rootstock Improves the Heat Tolerance of Cucumber by Regulating Photosynthetic and Antioxidant Defense Pathways.

High temperature is considered a critical abiotic stressor that is increasing continuously, which is severely affecting plant growth and development. The use of heat-resistant rootstock grafting is a viable technique that is practiced globally to improve plant resistance towards abiotic stresses. In this experiment, we explored the efficacy of bitter melon rootstock and how it regulates photosynthesis and the antioxidant defense system to alleviate heat stress (42 °C/32 °C) in cucumber.

Characterization of the CsPNG1 gene from cucumber and its function in response to salinity stress.

Peptide: N-glycanase (PNGase; EC 3.5.1.

Domino Reaction of Aromatic Aldehydes and 1,3-Indanediones for Construction of Bicyclo[2.2.2]octanes and Dibenzo[,]indeno[1',2':3,4]fluoreno[1,2-]oxonines.

Triethylamine promoted the pseudo-five-component reaction of aromatic aldehyde with four molecules of 1,3-indanediones in refluxing ethanol to give unique polycyclic bicyclo[2.2.2]octane derivatives containing bridged- and spiro-indanone scaffolds in good yields.

Isolation and characterization of S-Adenosylmethionine synthase gene from cucumber and responsive to abiotic stress.

S-adenosylmethionine synthetase (SAMS) catalyzes methionine and ATP to generate S-adenosyl-L-methionine (SAM). In plants, accumulating SAMS genes have been characterized and the majority of them are reported to participate in development and stress response. In this study, two putative SAMS genes (CsSAMS1 and CsSAMS2) were identified in cucumber (Cucumis Sativus L.

Selective synthesis of spirooxindoles via a two-step reaction of N-phenacylpyridinium bromide, 1,3-indanedione and N-alkylisations.

The three-component reaction of 1,3-indanedione and N-alkylisatins with two molecular N-phenacylpyridinium salts in dry acetonitrile in the presence of triethylamine resulted in unique functionalized spiro[indoline-3,4'-naphtho[1,2-b]furan] derivatives in good yields, which were successfully converted to spiro[indoline-3,2'-naphthalen]-4'-yl acetate derivatives by acylation with acetyl chloride in methylene dichloride and alkoxy-substituted spiro[benzo[h]chromene-5,3'-indolines] by acid-catalyzed etherification reaction in alcohol. The reaction mechanism involved the sequential cycloaddition of the in situ-generated pyridinium ylide to dipolarophilic enone, ring-opening of 1,3-indanedione, and selective annulation.

[Effects of exogenous spermidine and arbuscular mycorrhizal fungi on plant growth of cucumber].

Effects of spermidine (Spd) and arbuscular mycorrhizal fungi (AMF) on the growth and photosynthesis of cucumber (Cucumis sativus L., cv. Jinchun 2) seedlings, fruit yield and quality, microorganism and enzymatic activity in rhizosphere were investigated.

24-Epibrassinolide-induced alterations in the root cell walls of Cucumis sativus L. under Ca(NO) stress.

Brassinosteroids (BRs) can effectively alleviate the oxidative stress caused by Ca(NO) in cucumber seedlings. The root system is an essential organ in plants due to its roles in physical anchorage, water and nutrient uptake, and metabolite synthesis and storage. In this study, 24-epibrassinolide (EBL) was applied to the cucumber seedling roots under Ca(NO) stress, and the resulting chemical and anatomical changes were characterized to investigate the roles of BRs in alleviating salinity stress.

Tandem Double [3 + 2] Cycloaddition Reactions at Both C-1 and C-3 Atoms of -Cyanomethylisoquinolinium Ylide.

The base-promoted cycloaddition reaction of -cyanomethylisoquinolinium chloride with 2-arylidene-1,3-indanediones in dry tetrahydrofuran resulted in the expected spiro[indene-2,1'-pyrrolo[2,1-]isoquinoline] derivatives. However, the triethylamine-promoted three-component reaction of -cyanomethylisoquinolinium chloride, aromatic aldehydes, and two molecules of 1,3-indanediones in acetonitrile afforded unique spiro[benzo[]imidazo[5,1,2-]indolizine-4,2'-indene] derivatives in satisfactory yields through tandem double [3 + 2] cycloaddition reactions.

NaCl stress induces CsSAMs gene expression in Cucumis sativus by mediating the binding of CsGT-3b to the GT-1 element within the CsSAMs promoter.

The CsSAMs promoter is a salt-stress-inducible promoter containing three GT-1 elements that are sufficient for the salt-stress response. The transcription factor CsGT-3b was found to bind to the GT-1 element. The S-adenosyl-L-methionine synthase (SAMs) gene is among the functional genes induced during environmental stress.

NO accumulation alleviates H O -dependent oxidative damage induced by Ca(NO ) stress in the leaves of pumpkin-grafted cucumber seedlings.

Nitric oxide (NO) and hydrogen peroxide (H O ), two important signaling molecules, are stimulated in plants by abiotic stresses. In this study, we investigated the role of NO and its interplay with H O in the response of self-grafted (S-G) and salt-tolerant pumpkin-grafted (Cucurbita maxima × C. moschata) cucumber seedlings to 80 mM Ca(NO ) stress.

Two-carbon ring expansion of isatin: a convenient construction of a dibenzo[b,d]azepinone scaffold.

A unique two-carbon ring expansion of isatin has been achieved to conveniently construct the functionalized dibenzo[b,d]azepin-6-one scaffold in moderate to high yields, and the two carbon sources are different: one carbon is from the N-substituent of pyridinium bromide and the other is from indene-1,3-dione.

Proteomics analysis of compatibility and incompatibility in grafted cucumber seedlings.

Graft compatibility between rootstock and scion is the most important factor influencing the survival of grafted plants. In this study, we used two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF MS) to investigate differences in leaf proteomes of graft-compatible and graft-incompatible cucumber (Cucumis sativus L.)/pumpkin (Cucurbita L.

[Effects of exogenous 24-epibrassinolde on leaf morphology and photosynthetic characteristics of tomato seedlings under low light stress].

This study investigated the effects of exogenous 24-epibrassinolide (EBR) on the leaf morphology and photosynthetic characteristics of tomato seedlings (cv. Jiersi) cultured hydroponically under low light stress. The results showed that low light stress induced adaptive changes in the leaf morphology of tomato seedling.

Effects of grafting with pumpkin rootstock on carbohydrate metabolism in cucumber seedlings under Ca(NO3)2 stress.

This study investigated the effects of grafting on the carbohydrate status and the enzymes of carbohydrate metabolism in self-grafted and grafted cucumber seedlings using the salt-tolerant pumpkin rootstock 'Qingzhen 1' (Cucurbita maxima × Cucurbita moschata) under 80 mM Ca(NO3)2 stress for 6 d. The growth of self-grafted seedlings was significantly inhibited after the treatment of Ca(NO3)2 stress, whereas the inhibition of growth was alleviated in pumpkin rootstock-grafted seedlings. Ca(NO3)2 stress increased the contents of the total soluble sugar, sucrose and fructose, but decreased the starch content in rootstock-grafted leaves.

Effects of exogenous spermine on chlorophyll fluorescence, antioxidant system and ultrastructure of chloroplasts in Cucumis sativus L. under salt stress.

The effects of exogenous spermine (Spm) on plant growth, chlorophyll fluorescence, ultrastructure and anti-oxidative metabolism of chloroplasts were investigated in Cucumis sativus L. under NaCl stress. Salt stress significantly reduced plant growth, chlorophylls content and F(v)/F(m).

[Effects of brassinolide on the leaf mitochondria and chloroplast ultrastructure and photosynthesis of cucumber seedlings under hypoxia stress].

A hydroponic experiment was conducted to investigate the effects of 24-epibrassinolide (EBR) on the leaf mitochondria and chloroplast ultrastructure and photosynthesis of cucumber seedlings under hypoxia stress. Under the stress, the apparent quantum yield (AQY) and carboxylation efficiency (CE) decreased significantly, while the light compensation point (LCP), dark breathing rate (R(d)), and CO2 compensation point (CCP) had a significant increase. The application of EBR increased the CE significantly by 29.

[Salt stress tolerance of cucumber-grafted rootstocks].

Taking 4 different Cucurbita maxima x C. moschata rootstocks for cucumber (Cucumis sativus) as test materials, a solution culture experiment was conducted to study their growth and antioxidative enzyme activities under the stresses of Ca(NO3)2 and NaCl, with the salt stress tolerance of the rootstocks evaluated by subordinate function. At 30 mmol x L(-1) of Ca (NO3)2 or 45 mmol x L(-1) of NaCl, the growth of the rootstock seedlings was improved; but at 60 and 120 mmol x L(-1) of Ca(NO3)2 or 90 and 180 mmol x L(-1) of NaCl, the growth and the antioxidative systems of the seedlings were inhibited, and the salt injury index of 'Qingzhen No.

[Effects of arbuscular mycorrhiza fungi (AMF) on the plant growth, fruit yield, and fruit quality of cucumber under salt stress].

By adopting organic substrate culture, and salt-sensitive cucumber variety 'Jinchun No. 2' was used as test material, this paper studied the effects of inoculating arbuscular mycorrhiza fungi (AMF) on the plant growth, fruit yield, and fruit quality of cucumber under salt stress. AMF-inoculation could effectively promote the plant growth and nutrient uptake, and improve the fruit yield and fruit nutrient quality, compared with ordinary cultivation.

[Effects of exogenous 24-epibrassinolide on the leaf photosynthetic characteristics and polyamines content of cucumber seedlings under hypoxia stress].

A water culture experiment with 1/2 Hoagland solution was carried out to study the effects of exogenous 24-epibrassinolide (EBR) on the leaf photosynthetic characteristics and polyamines (PAs) content of cucumber seedlings under hypoxia stress. Under the stress, the leaf net photosynthetic rate (Pn), stomatal conductance (g(s)), transpiration rate (Tr), and intercellular CO2 concentration (Ci) decreased significantly while the chlorophyll content was in adverse, and the seedling growth was inhibited. Hypoxia stress increased the leaf Put, Spd, and Spm contents and Put/PAs ratio significantly, but decreased the (Spd+Spm)/Put.

Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine.

With the objective to clarify the physiological significance of polyamines (PAs) in the photosynthetic apparatus, the present study investigated the effects of salt stress with and without foliar application of putrescine (Put) on the structure and function of the photosynthetic apparatus in cucumber. Salt stress at 75 mM NaCl for 7 days resulted in a severe reduction of photosynthesis. The fast chlorophyll afluorescence transient analysis showed that salt stress inhibited the maximum quantum yield of PSII photochemistry (F(v)/F(m)), mainly due to damage at the receptor side of PSII.

[Effects of exogenous spermidine on lipid peroxidation and membrane proton pump activity of cucumber seedling leaves under high temperature stress].

Taking a relatively heat-resistant cucumber (Cucumis sativus) cultivar 'Jinchun No. 4' as test material, a sand culture experiment was conducted in growth chamber to investigate the effects of foliar spraying spermidine (Spd) on the lipid peroxidation, membrane proton pump activity, and corresponding gene expression of cucumber seedling leaves under high temperature stress. Compared with the control, foliar spraying Spd increased the plant height, stem diameter, dry and fresh mass, and leaf area significantly, and inhibited the increase of leaf relative conductivity, malondialdehyde (MDA) content, and lipoxygenase (LOX) activity effectively.

[Thermal dissipation pathway in cucumber seedling leaves under hypoxia stress].

A water culture experiment was conducted to study the relationship between photosynthetic thermal dissipation and xanthophyll cycle in cucumber seedling leaves under hypoxia stress (the dissolved oxygen concentration in nutrient solution was 0.9-1.1 mg x L(-1)).

Proteomic analysis of cucumber seedling roots subjected to salt stress.

To understand metabolic modifications in plants under salt stress, the physiological and biochemical responses of cucumber (Cucumis sativus L. cv. Jinchun No.

Effects of exogenous putrescine on gas-exchange characteristics and chlorophyll fluorescence of NaCl-stressed cucumber seedlings.

The effects of 10 mM putrescine (Put) treated by spraying on leaves on growth, chlorophyll content, photosynthetic gas-exchange characteristics, and chlorophyll fluorescence were investigated by growing cucumber plants (Cucumis sativus L. cv. ChangChun mici) using hydroponics with or without 65 mM NaCl as a salt stress.

[Effects of root zone hypoxia on respiratory metabolism of cucumber seedlings roots].

With the seedlings of Lübachun No. 4, a hypoxia-resistant cultivar, and Zhongnong No. 8, a hypoxia-sensitive cultivar, as test materials, and by the method of solution culture, this paper studied the effects of root zone hypoxia on their roots' respiratory metabolism.