Salicylic acid improves chilling tolerance via CsNPR1-CsICE1 interaction in grafted cucumbers.

Salicylic acid (SA) plays a role in the regulation of grafting-induced cold tolerance. However, the molecular mechanism behind it is still unknown. Here, we established that the phenylalanine ammonia-lyase (PAL) pathway-dependent elevate in SA content in grafted cucumber leaves was not only synthesized in the leaves but also transported from the roots under chilling stress.

Overexpression Promoted Photosynthesis in Tomato under Chilling Stress by Improving CO Assimilation and Alleviating Photoinhibition.

Chilling causes a significant decline in photosynthesis in tomato plants. Tomato tryptophan decarboxylase gene 1 () is the first rate-limiting gene for melatonin (MT) biosynthesis and is involved in the regulation of photosynthesis under various abiotic stresses. However, it is not clear whether participates in the photosynthesis of tomato under chilling stress.

Effects of rotted corn straw on soil environment, yield, and quality of cucumber.

Aiming at solving the problems of soil environment deterioration and the decline of both yield and quality caused by excessive application of chemical fertilizer, we investigated the effects of rotted corn straw on the soil environment of root zone, yield and quality of cucumber with 'Jinyou 35' cucumber as the experimental material. There were three treatments, namely, combined application of rotted corn straw and chemical fertilizer (T, the total nitrogen fertilizer application were 450 kg N·hm, of which 9000 kg·hm rotted corn straw was used as the subsoil fertilizer, and the rest was supplemented with chemical fertilizer), pure chemical fertilizer (T, the total nitrogen fertilizer application was the same as T) and no fertilization (control). The results showed that the content of soil organic matter in root zone soil in T treatment was much higher, but no difference between T treatment and the control, after two continuous plantings in one year.

Comparative transcriptome analysis of grafting to improve chilling tolerance of cucumber.

Grafting with pumpkin as rootstock could improve chilling tolerance of cucumber; however, the underlying mechanism of grafting-induced chilling tolerance remains unclear. Here, we analyzed the difference of physiological and transcriptional level between own-rooted (Cs/Cs) and hetero-grafted (Cs/Cm) cucumber seedlings under chilling stress. The results showed that grafting with pumpkin significantly alleviated the chilling injury as evidenced by slightly symptoms, lower contents of electrolyte leakage (EL), malondialdehyde (MDA), hydrogen peroxide (HO), and superoxide anion (O) and higher relative water content in Cs/Cm seedlings compared with Cs/Cs seedlings under chilling stress.

Abscisic Acid Mediates Salicylic Acid Induced Chilling Tolerance of Grafted Cucumber by Activating HO Biosynthesis and Accumulation.

Grafting is widely applied to enhance the tolerance of some vegetables to biotic and abiotic stress. Salicylic acid (SA) is known to be involved in grafting-induced chilling tolerance in cucumber. Here, we revealed that grafting with pumpkin (, ) as a rootstock improved chilling tolerance and increased the accumulation of SA, abscisic acid (ABA) and hydrogen peroxide (HO) in grafted cucumber () leaves.

[Alleviating effect of exogenous melatonin and calcium on the peroxidation damages of cucumber under high temperature stress].

To explore whether there is an interaction between melatonin (MT) and calcium (Ca) in regulating heat tolerance of plants, we analyzed the response of endogenous MT and Ca to heat stress, and examined the effect of MT and Ca on the reactive oxygen (ROS) accumulation, antioxidant system, and transcripts of heat shock factor () and heat shock proteins () of cucumber seedlings under high temperature stress. Seedlings were foliar sprayed with 100 μmol·L MT, 10 mmol·L CaCl, 3 mmol·L ethylene glycol tetraacetic acid (EGTA, Ca chelating agent) +100 μmol·L MT, 0.05 mmol·L chlorpromazine (calmodulin antagonist, CPZ) +100 μmol·L MT, 100 μmol·L p-chlorophenylalanine (p-CPA, inhibitor of MT) +10 mmol·L CaCl or deionized water (HO), respectively.

[Effects of fulvic acid on photosynthetic characteristics, yield and quality of cucumber under drought stress].

Fulvic acid (FA) participates in the regulation of drought stress tolerance in plants, but the underlying mechanisms remain unclear. We carried out an experiment with cucumber cultivar 'Jinyou 35' as the test material and the polyethylene glycol (PEG-6000) being used to simulate drought stress. The concentration effect of FA on drought alleviation of cucumber as well as the effect of FA on photosynthetic enzymes activities, chloroplast ultrastructure, fluorescence parameters, water use efficiency, yield and quality of cucumber plants were studied through spraying FA with different concentrations (0, 100, 300, 500, 700 and 900 mg·L).

Melatonin Positively Regulates Both Dark- and Age-Induced Leaf Senescence by Reducing ROS Accumulation and Modulating Abscisic Acid and Auxin Biosynthesis in Cucumber Plants.

Melatonin (MT), as a signaling molecule, plays a vital role in regulating leaf senescence in plants. This study aimed to verify the antioxidant roles of MT in delaying dark- or age-induced leaf senescence of cucumber plants. The results showed that endogenous MT responds to darkness and overexpression of , the key gene of MT synthesis, and delays leaf senescence stimulated by darkness, as manifested by significantly lower malonaldehyde (MDA) and reactive oxygen species (ROS) contents as well as higher activities and gene expression of antioxidant enzymes compared to the control.

HO participates in ABA regulation of grafting-induced chilling tolerance in cucumber.

Rootstock provides more abscisic acid (ABA) content to scions to increase the chilling tolerance of seedlings. HO is involved in ABA regulation of grafting-induced chilling tolerance of cucumber. Here we examined the role of ABA in the response of grafted cucumber to chilling stress.

Effects of the Chloroplast Fructose-1,6-Bisphosphate Aldolase Gene on Growth and Low-Temperature Tolerance of Tomato.

Tomato () is one of the most important greenhouse vegetables, with a large cultivated area across the world. However, in northern China, tomato plants often suffer from low-temperature stress in solar greenhouse cultivation, which affects plant growth and development and results in economic losses. We previously found that a chloroplast aldolase gene in tomato, , plays an important role in the Calvin-Benson cycle (CBC), and its expression level and activity can be significantly altered when subjected to low-temperature stress.

Hydrogen Sulfide Improves the Cold Stress Resistance through the CsARF5-CsDREB3 Module in Cucumber.

As an important gas signaling molecule, hydrogen sulfide (HS) plays a crucial role in regulating cold tolerance. HS cooperates with phytohormones such as abscisic acid, ethylene, and salicylic acid to regulate the plant stress response. However, the synergistic regulation of HS and auxin in the plant response to cold stress has not been reported.

HO Functions as a Downstream Signal of IAA to Mediate HS-Induced Chilling Tolerance in Cucumber.

Hydrogen sulfide (HS) plays a crucial role in regulating chilling tolerance. However, the role of hydrogen peroxide (HO) and auxin in HS-induced signal transduction in the chilling stress response of plants was unclear. In this study, 1.

Nitric Oxide Functions as a Downstream Signal for Melatonin-Induced Cold Tolerance in Cucumber Seedlings.

Melatonin (MT) and nitric oxide (NO) are two multifunctional signaling molecules that are involved in the response of plants to abiotic stresses. However, how MT and NO synergize in response to cold stress affecting plants is still not clear. In this study, we found that endogenous MT accumulation under cold stress was positively correlated with cold tolerance in different varieties of cucumber seedlings.

Salicylic Acid Is Involved in Rootstock-Scion Communication in Improving the Chilling Tolerance of Grafted Cucumber.

Salicylic acid (SA) has been proven to be a multifunctional signaling molecule that participates in the response of plants to abiotic stresses. In this study, we used cold-sensitive cucumber and cold-tolerant pumpkin as experimental materials to examine the roles of SA in root-shoot communication responses to aerial or/and root-zone chilling stress in own-root and hetero-root grafted cucumber and pumpkin plants. The results showed that pumpkin () rootstock enhanced the chilling tolerance of grafted cucumber, as evidenced by the observed lower levels of electrolyte leakage (EL), malondialdehyde (MDA), and higher photosynthetic rate (Pn) and gene expression of Rubisco activase (RCA).

[Hydrogen sulfide acted as a downstream signal was involved in the regulation of salicylic acid on photosynthesis of cucumber seedlings under low temperature and low light intensity].

Both salicylic acid (SA) and hydrogen sulfide (HS) play an important role in regulating plant growth and development and physiological metabolism under abiotic stresses. As signal molecules, the interaction between them in regulating cucumber photosynthesis under low temperature and low light is still unclear. Here, we examined the regulation and interaction of SA and HS on photosynthesis in cucumber seedlings under low temperature (8 ℃/5 ℃, day/night) and low light (100 μmol·m·s).

Hydrogen sulfide is required for salicylic acid-induced chilling tolerance of cucumber seedlings.

Salicylic acid (SA) and hydrogen sulfide (HS) have been proved to be multifunctional signal molecules to participate in the response of plants to abiotic stresses. However, it is still unclear whether there is interaction between SA and HS in response to chilling intensity of cucumber seedlings. Here, we found SA was sensitive to chilling intensity.

Auxin acts as a downstream signaling molecule involved in hydrogen sulfide-induced chilling tolerance in cucumber.

This report proves a cross talk between HS and IAA in cold stress response, which has presented strong evidence that IAA acts as a downstream signal mediating the HS-induced stress tolerance in cucumber seedlings. We evaluated changes in endogenous hydrogen sulfide (HS) and indole-3-acetic acid (IAA) emission systems, and the interactive effect of exogenous HS and IAA on chilling tolerance in cucumber seedlings. The results showed that chilling stress increased the activity and relative mRNA expression of L-/D-cysteine desulfhydrase (L-/D-CD), which in turn induced the accumulation of endogenous HS.

Physiological response and transcription profiling analysis reveal the role of glutathione in HS-induced chilling stress tolerance of cucumber seedlings.

Recent reports have uncovered the multifunctional role of HS in the physiological response of plants to biotic and abiotic stresses. Here, we studied whether NaHS (an HS donor) pretreatment could provoke the tolerance of cucumber (Cucumis sativus L.) seedlings subsequently exposed to chilling stress and whether glutathione was involved in this process.

Response of water balance and nitrogen assimilation in cucumber seedlings to CO enrichment and salt stress.

The effects of CO enrichment on water balance and nitrogen (N) assimilation in cucumber (Cucumis sativus L. cv. Jinyou No.

Overexpression of transketolase gene promotes chilling tolerance by increasing the activities of photosynthetic enzymes, alleviating oxidative damage and stabilizing cell structure in Cucumis sativus L.

Despite being a key enzyme of Cavin cycle, transketolase (TK) is believed to be related to abiotic resistance in higher plants. However, how TK affects chilling tolerance still remains largely unknown. Here, we describe the effect of overexpression of the Cucumis sativa TK gene (CsTK) on growth, photosynthesis, ROS metabolism and cell ultrastructure under chilling stress.

Metabolomics analysis reveals that elevated atmospheric CO alleviates drought stress in cucumber seedling leaves.

Elevated atmospheric CO alleviates moderate to severe drought stresses at physiological level in cucumber. To investigate the underlying metabolic mechanisms, cucumber seedlings were treated with two [CO] and three water treatments combinations, and their leaves were analyzed using a non-targeted metabolomics approach. The results showed that elevated [CO] changed 79 differential metabolites which were mainly associated with alanine, aspartate and glutamate metabolism; arginine and proline metabolism; TCA cycle; and glycerophospholipid metabolism under moderate drought stress.

Secondary and sucrose metabolism regulated by different light quality combinations involved in melon tolerance to powdery mildew.

We evaluated the effect of different light combinations on powdery mildew resistance and growth of melon seedlings. Light-emitting diodes were used as the light source and there were five light combinations: white light (420-680 nm); blue light (460 nm); red light (635 nm); RB31 (ratio of red and blue light, 3: 1); and RB71 (ratio of red and blue light, 7: 1). Compared with other treatments, blue light significantly decreased the incidence of powdery mildew in leaves of melon seedlings.