Suitable illumination intensity is essential for preserving the quality of cucumber (Cucumis sativus L.) seedlings during storage.

Continuous darkness decreases seedling quality during storage, whereas appropriate light quality and intensity can overcome these negative effects. In this study, we determined the light intensity, storage time (ST), and storage temperature suitable for cucumber (Cucumis sativa L.) seedlings. We stored cucumber seedlings under four different photosynthetic photon flux densities (PPFDs; 0, 15, 30, and 45 μmol·m-2·s-1) at 12°C, and examined how the morphological, physiological, and photosynthetic changes in seedlings during storage affected their ability to recover after transplanting. Our results indicated that at least 15 μmol·m-2·s-1 PPFD was needed for cucumber seedlings stored in the dark for 2 or 4 d, and at least 30 μmol·m-2·s-1 PPFD was needed when the ST was extended to 6 d. Overall, our results showed that cucumber seedlings require light-emitting diode (LED) illumination during storage to maintain their quality and recovery ability

Irrigation has more influence than fertilization on leaching water quality and the potential environmental risk in excessively fertilized vegetable soils.

Excessive fertilization is a common agricultural practice that often negatively influence soil and environmental quality in intensive vegetable production systems in China. To reduce negative effects of excessive fertilization, current studies generally focused on fertilizer management but not irrigation. In this study, we investigated the effects of fertilization and irrigation on soil properties, leaching water characteristics, plant growth, cucumber yield, irrigation water use efficiency (IWUE) and partial factor productivity of nitrogen (PFPN) in a double cropping system. The treatments included (i) conventional irrigation with conventional N fertilization (IcNc), (ii) optimal irrigation with conventional N fertilization (IoNc), (iii) conventional irrigation with optimal N fertilization (IcNo), and (iv) optimal irrigation with optimal N fertilization (IoNo). In general, fertilization merely influenced concentrations of nitrate (NO3-), phosphorus (P) and potassium (K), but did not affect most leaching water characteristics. In contrast, irrigation influenced pH, EC and concentrations of P, K, Ca, Mg, Na and Cu. Cumulative leached amounts of NO3-, P, K, Ca, Mg, Na, Fe, Cu and Zn were significantly decreased by optimal irrigation as compared to conventional irrigation under same fertilization conditions, but not by optimal fertilization as compared to conventional fertilization under same irrigation conditions. The leachate volume was strongly positively correlated with cumulative leached amounts of all tested elements, and these relationships were obviously influenced by irrigation but not fertilization. The IoNo treatment significantly increased both IWUE and PFPN as compared to the IcNc treatment. However, the IcNo treatment only enhanced PFPN, while the IoNc treatment improved IWUE, when compared to the IcNc treatment. Our results suggested that irrigation has more influence than fertilization on leaching water quality and that the optimal irrigation combined with optimal fertilization was efficient in reducing the potential environmental risk caused by excessive fertilization in intensive vegetable production systems

Genome-Wide Identification and Chilling Stress Analysis of the NF-Y Gene Family in Melon

The nuclear factor Y (NF-Y) transcription factor contains three subfamilies: NF-YA, NF-YB, and NF-YC. The NF-Y family have been reported to be key regulators in plant growth and stress responses. However, little attention has been given to these genes in melon (Cucumis melo L.). In this study, twenty-five NF-Ys were identified in the melon genome, including six CmNF-YAs, eleven CmNF-YBs, and eight CmNF-YCs. Their basic information (gene location, protein characteristics, and subcellular localization), conserved domains and motifs, and phylogeny and gene structure were subsequently analyzed. Results showed highly conserved motifs exist in each subfamily, which are distinct between subfamilies. Most CmNF-Ys were expressed in five tissues and exhibited distinct expression patterns. However, CmNF-YA6, CmNF-YB1/B2/B3/B8, and CmNF-YC6 were not expressed and might be pseudogenes. Twelve CmNF-Ys were induced by cold stress, indicating the NF-Y family plays a key role in melon cold tolerance. Taken together, our findings provide a comprehensive understanding of CmNF-Y genes in the development and stress response of melon and provide genetic resources for solving the practical problems of melon production

Melatonin Has the Potential to Alleviate Cinnamic Acid Stress in Cucumber Seedlings

Cinnamic acid (CA), which is a well-known major autotoxin secreted by the roots in cucumber continuous cropping, has been proven to exhibit inhibitory regulation of plant morphogenesis and development. Melatonin (MT) has been recently demonstrated to play important roles in alleviating plant abiotic stresses. To investigate whether MT supplementation could improve cucumber seedling growth under CA stress, we treated cucumber seeds and seedlings with/without MT under CA- or non-stress conditions, and then tested their effects on cucumber seedling growth, morphology, nutrient element content, and plant hormone. Overall, 10 μM MT best rescued cucumber seedling growth under 0.4 mM CA stress. MT was found to alleviate CA-stressed seedling growth by increasing the growth rates of cotyledons and leaves and by stimulating lateral root growth. Additionally, MT increased the allocation of newly gained dry weight in roots and improved the tolerance of cucumber seedlings to CA stress by altering the nutrient elements and hormone contents of the whole plant. These results strongly suggest that the application of MT can effectively improve cucumber seedling tolerance to CA stress through the perception and integration of morphology, nutrient element content and plant hormone signaling crosstalk

A new strategy for volumetric-modulated arc therapy planning using AutoPlanning based multicriteria optimization for nasopharyngeal carcinoma

Abstract Background A new strategy for making the appropriate choice of the representative optimization parameters in planning processes and accurate selection criteria during Pareto surface navigation for general multicriteria optimization (MCO) was recommended in the study. The purpose was to combine both benefits of AutoPlanning optimization and MCO (APMCO) for achieving an individual volumetric-modulated arc therapy (VMAT) plan according to the clinically achieved patient-specific tradeoff among conflicting priorities. The preclinical investigation of this optimization approach for nasopharyngeal carcinoma (NPC) radiotherapy was performed and compared to general MCO VMAT. Methods A total of 60 NPC patients with various stages were enrolled in this study. General MCO and APMCO plans were generated for each patient on the treatment planning system. The differences between two planning schemes were evaluated and compared. Results All plans were capable of achieving the prescription requirement. The planning target volume coverage and conformation number were remarkably similar between general MCO and APMCO plans. There were no significant differences in most of organs at risk (OARs) sparing. However, in APMCO plans, relatively remarkable decreases were observed in the mean dose (Dmean) to the glottic larynx and pharyngeal constrictor muscles. The reductions of average Dmean to the two OARs were 10.5% (p < 0.0001) and 8.4% (p < 0.0001), respectively. APMCO technique was found to increase the planning time for an average of approximately 5 h and did not lead to a significant increase of monitor units compared to general MCO. Conclusions The potential of the APMCO strategy is best realized with a clinical implementation that exploits individual generation of Pareto surface representations without manual interaction. It also assists physicians to ensure navigation in a more efficient and straightforward manner

Data_Sheet_2_Knock-Down of CsNRT2.1, a Cucumber Nitrate Transporter, Reduces Nitrate Uptake, Root length, and Lateral Root Number at Low External Nitrate Concentration.DOCX

<p>Nitrogen (N) is a macronutrient that plays a crucial role in plant growth and development. Nitrate (NO3-) is the most abundant N source in aerobic soils. Plants have evolved two adaptive mechanisms such as up-regulation of the high-affinity transport system (HATS) and alteration of the root system architecture (RSA), allowing them to cope with the temporal and spatial variation of NO3-. However, little information is available regarding the nitrate transporter in cucumber, one of the most important fruit vegetables in the world. In this study we isolated a nitrate transporter named CsNRT2.1 from cucumber. Analysis of the expression profile of the CsNRT2.1 showed that CsNRT2.1 is a high affinity nitrate transporter which mainly located in mature roots. Subcellular localization analysis revealed that CsNRT2.1 is a plasma membrane transporter. In N-starved CsNRT2.1 knock-down plants, both of the constitutive HATS (cHATS) and inducible HATS (iHATS) were impaired under low external NO3- concentration. Furthermore, the CsNRT2.1 knock-down plants showed reduced root length and lateral root numbers. Together, our results demonstrated that CsNRT2.1 played a dual role in regulating the HATS and RSA to acquire NO3- effectively under N limitation.</p

Is it possible for knowledge-based planning to improve intensity modulated radiation therapy plan quality for planners with different planning experiences in left-sided breast cancer patients?

Abstract Background Knowledge-based planning (KBP) is a promising technique that can improve plan quality and increase planning efficiency. However, no attempts have been made to extend the domain of KBP for planners with different planning experiences so far. The purpose of this study was to quantify the potential gains for planners with different planning experiences after implementing KBP in intensity modulated radiation therapy (IMRT) plans for left-sided breast cancer patients. Methods The model libraries were populated with 80 expert clinical plans from treated patients who previously received left-sided breast-conserving surgery and IMRT with simultaneously integrated boost. The libraries were created on the RapidPlanTM. 6 planners with different planning experiences (2 beginner planners, 2 junior planners and 2 senior planners) generated manual and KBP optimized plans for additional 10 patients, similar to those included in the model libraries. The plan qualities were compared between manual and KBP plans. Results All plans were capable of achieving the prescription requirement. There were almost no statistically significant differences in terms of the planning target volume (PTV) coverage and dose conformality. It was demonstrated that the doses for most of organs-at-risk (OARs) were on average lower or equal in KBP plans compared to manual plans except for the senior planners, where the very small differences were not statistically significant. KBP data showed a systematic trend to have superior dose sparing at most parameters for the heart and ipsilateral lung. The observed decrease in the doses to these OARs could be achieved, particularly for the beginner and junior planners. Many differences were statistically significant. Conclusions It is feasible to generate acceptable IMRT plans after implementing KBP for left-sided breast cancer. KBP helps to effectively improve the quality of IMRT plans against the benchmark of manual plans for less experienced planners without any manual intervention. KBP showed promise for homogenizing the plan quality by transferring planning expertise from more experienced to less experienced planners

Data_Sheet_1_Knock-Down of CsNRT2.1, a Cucumber Nitrate Transporter, Reduces Nitrate Uptake, Root length, and Lateral Root Number at Low External Nitrate Concentration.PDF

<p>Nitrogen (N) is a macronutrient that plays a crucial role in plant growth and development. Nitrate (NO3-) is the most abundant N source in aerobic soils. Plants have evolved two adaptive mechanisms such as up-regulation of the high-affinity transport system (HATS) and alteration of the root system architecture (RSA), allowing them to cope with the temporal and spatial variation of NO3-. However, little information is available regarding the nitrate transporter in cucumber, one of the most important fruit vegetables in the world. In this study we isolated a nitrate transporter named CsNRT2.1 from cucumber. Analysis of the expression profile of the CsNRT2.1 showed that CsNRT2.1 is a high affinity nitrate transporter which mainly located in mature roots. Subcellular localization analysis revealed that CsNRT2.1 is a plasma membrane transporter. In N-starved CsNRT2.1 knock-down plants, both of the constitutive HATS (cHATS) and inducible HATS (iHATS) were impaired under low external NO3- concentration. Furthermore, the CsNRT2.1 knock-down plants showed reduced root length and lateral root numbers. Together, our results demonstrated that CsNRT2.1 played a dual role in regulating the HATS and RSA to acquire NO3- effectively under N limitation.</p