Physiological responses of hollyhock (Alcea rosea L.) to drought stress

© 2024 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/horticulturae10080841Hollyhock (Alcea rosea L.) is an aromatic, ornamental/medicinal plant species for which the selection of drought-tolerant varieties based on physio-chemical traits is desirable. The data presented resulted from a field experiment. This experiment was designed as a split-plot, based on a randomized complete block design, in which the main plots consisted of the three irrigation regimes (30, 60 and 80% permissible discharge moisture available in the soil), and the subplots consisted of nine hollyhock varieties. Photosynthetic pigments, Fv/Fm, proline content and selected antioxidant enzymes were measured throughout the period of induced drought stress. The data obtained illustrate the nature of the physiological response of hollyhock to drought stress. Based on the measured traits the varieties Isfahan 1, Shiraz 1 and Tabriz were shown to display the highest degree of resistance to drought stress. These data suggest that the effect of drought stress is dependent upon the drought level, variety and the trait in question. In this regard, future plant breeders for this species may find it useful to utilize ascorbate peroxidase (APX), catalase (CAT) and guayacol peroxidase (POX) activities as biochemical markers to select for drought-tolerant genotypes. As such, hollyhock can be considered a promising ornamental/medicinal species for cultivation in semi-arid environments

Differential responses of Hollyhock (Alcea rosea L.) varieties to salt stress in relation to physiological and biochemical parameters

© 2024 The Authors. Published by SpringerNature. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1038/s41598-024-58537-2The response of 14 Hollyhock (Alcea rosea L.) varieties to salinity were evaluated in a field experiment over two growing seasons. Carotenoid, Chl a, Chl b, total Chl, proline and MDA content, CAT, APX and GPX activity and petal and seeds yields were determined in order to investigate the mechanism of salt tolerance exhibited by Hollyhock, and too identify salt tolerant varieties. Overall, the photosynthetic pigment content,petal and seed yields were reduced by salt stress. Whereas the proline and MDA content, and the CAT, APX and GPX activities increased as salt levels increased. However, the values of the measured traits were dependent upon the on the level of salt stress, the Varietie and the interaction between the two variables. Based upon the smallest reduction in petal yield, the Masouleh variety was shown to be the most salt tolerant, when grown under severe salt stress. However, based upon the smallest reduction in seed yield, Khorrmabad was the most tolerant variety to severe salt stress. These data suggest that the selection of more salt tolerant Hollyhock genotypes may be possible based upon the wide variation in tolerance to salinity exhibited by the varieties tested.This work was supported by Isfahan University of Technology, Iran.Published onlin

Changes in secondary metabolite production in response to salt stress in Alcea rosea L.

© 2024 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/horticulturae10020139The effect of three levels of salinity on physio-biochemical traits in 10 Alcea rosea (hollyhock) varieties were evaluated. It was observed that salt stress increased both the total phenolic content (TPC) and total flavonoid content (TFC) in some varieties and decreased them in others. The greatest increases in both TPC and TFC were recorded in the Saman variety (104% and 62%, respectively) when cultivated under severe salt stress, indicating that this is the most salt-tolerant variety amongst those tested. The most abundant phenolic compound recorded was ellagic acid, and the phenolic compounds that showed the greatest increases in concentration due to salt stress were p-coumaric acid (87% in the Isfahan variety) and chlorogenic acid (142% in the Mahallat variety). Salt stress was also shown to decrease the production of diphenyl-2-picrylhydrazyl (DPPH) in all varieties. The highest concentration of DPPH (133%) was recorded in the Shiraz 1 variety, grown under conditions of severe salt stress. Salt stress also increased the mucilage content present in the petals, leaves, and seeds of some of the selected varieties. These data suggest that the selection of salt-tolerant varieties of hollyhock for direct cultivation or for use in future breeding programs is feasible.This research received no external funding, and the APC was funded by University of Brescia

Physiological, biochemical, and agronomic trait responses of nigella sativa genotypes to water stress

© 2022 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://www.mdpi.com/2311-7524/8/3/193Water stress may affect the growth, physiology, morphology, biochemistry, and productivity of Nigella sativa (black cumin), a medicinal and aromatic plant. Measuring these parameters under various irrigation regimes could provide useful information for successful genotype selection and breeding. Therefore, these agronomically significant features were evaluated in ten black cumin genotypes (Afghanistan, Pakistan, Syria, India, Arak, Isfahan, Semirom, Shahreza, Shahrekord, and Mashhad) under three irrigation regimes (40% (I1), 60% (I2), and 80% (I3) of permissible moisture discharge) during the 2017 to 2018 growing seasons. Water stress was shown to increase the levels of carotenoids (Cars), proline, total soluble carbohydrates (TSC), malondialdehyde (MDA), hydrogen peroxide (H2O2), catalase (CAT), and ascorbate peroxidase (APX) activities but reduced the relative water content (RWC) and chlorophyll content. The highest increases in Cars, TSC, proline, CAT, and APX were noted in the Arak, Isfahan, Semirom, Shahreza, Shahrekord, and Mashhad genotypes under the I3 water regime, respectively. At the same time, the lowest decrease was observed in chlorophyll, H2O2, and relative water content (RWC) in Semirom. According to the stress susceptibility index, the most resistant genotypes were Shahrekord under I2 and Semirom under I3. These data demonstrate that the irrigation regimes affected the physiological, biochemical, and morphological features of black cumin both qualitatively and quantitatively, although the impact varied depending upon the genotype, irrigation regime, and traits. As such, the results presented represent valuable information with which to inform future selection and breeding programs for drought-tolerant black cumin. This is of particular significance considering global climate change

Salicylic acid affects mycorrhizal features, antioxidant enzyme activities and seed yield of linseed under water-deficit stress in open-field conditions

The research aims were to study salicylic acid (SA) effects on mycorrhiza [hyphal width (HW), vesicle diameter (VD) and mycorrhizal colonization (MC)] and interaction between them on greenness index (GI), drought tolerance index (DTI), antioxidant enzymes activities, and seed yield of linseed under drought. A factorial experiment was conducted in an open-field place with mycorrhiza [non-inoculation, Funneliformis mosseae (FM), and Rhizoglomus intraradices (RI)], SA (250 μM and non-SA), and irrigation levels [100%, 70%, and 40% field capacity (FC)] as treatments. Severe drought increased VD, MC, superoxide dismutase (SOD), ascorbate peroxidase (APX), and peroxidase activities while decreased GI, DTI, and yield. The RI-linseed had higher MC, GI, SOD, and glutathione reductase (GR) activities, but FM-linseed had greater VD and yield under drought. Inoculated linseed with both mycorrhiza showed a reduction in DTI and yield under SA than non-SA. In RI-linseed, SA increased GI, MC, HW, VD, catalase and GR, but decreased in FM-plants. Mycorrhiza (particularly RI) alleviated drought (40% FC)-caused negative effects on linseed via the improvement of SOD, APX, and GI. Regardless of other treatments, SA had negative effects on HW and VD, but SA effects varied depending on mycorrhizal species so that SA increased HW, VD, and MC in RI. Due to the positive correlation between MC and HW, SA reduces FM colonization by reducing the HW of FM. Totally, SA along with RI species can mitigate the harmful effects of drought and improve tolerance via increasing MC, HW, VD, catalase, peroxidase, and GR activities

Remifentanil-Ketamine versus Fentanyl-Ketamine sedation in patients undergoing phacoemulsification with topical anesthesia: comparison of intraocular pressure changes and sedation quality

BACKGROUND: Narcotics and sedatives can reduce intraocular pressure. This study was performed to evaluate the effect of remifentanil plus ketamine on intraocular pressure and sedation quality in comparison with fentanyl plus ketamine during and after operation in patients undergoing phacoemulsification with topical anesthesia.METHODS: Forty four patients were randomized into two groups to receive either a continuous infusion of remifentanil (0.2 &micro;g/kg/min for 4 min and then 0.1 &micro;g/kg/min: Group R, n=22) or bolus intravenous fentanyl (1.5 &micro;g/kg: Group F, n=22) for sedation. Patients in both groups received low dose ketamine (0.15 mg/kg) intravenously. Topical anesthesia was performed using tetracaine 0.5% eye drop in both eyes. Intraocular pressure was measured in non-operative eye before sedation (baseline), 2 minutes after sedation, before intraocular lens insertion, at the end of operation and 15 minutes after the end of operation using Schi&ouml;tz tonometer. Sedation, cooperation, satisfaction and pain scores and also postoperative nausea and vomiting were recorded in all patients. Surgeon satisfaction scores were evaluated at the end of operation.RESULTS: The intraocular pressure did not differ significantly between the two groups throughout the study. The mean (SD) intraocular pressures 2 minutes after sedation, before intraocular lens insertion, at the end of operation and 15 minutes after the end of operation in recovery room were all less than that of baseline in both groups, but the baseline value was decreased only significantly (P CONCLUSIONS: Combination of remifentanil infusion and intravenous ketamine did not offer any advantages over the combination of intravenous fentanyl and ketamine in order to prevent intraocular pressure rising during phacoemulsification. The lower incidence of postoperative nausea and vomiting and higher rate of appropriate sedation in fentanyl group suggested fentanyl as a more suitable medication for systemic sedation compared with remifentanil.KEY WORDS: Fentanyl, remifentanil, intraocular pressure, phacoemulsification, topical anesthesia.</ul

Comparison of standard and low dose intraoperative mitomycin c in prevention of corneal hazeafter photorefractive keratectomy

Background: This study aimed to compare two doses of Mitomycin C in reducing haze formation after photorefractive keratectomy. Methods: 170 eyes of 85 patients enrolled; in each patient one eye randomly assigned to be treated by low dose intraoperative MMC (LDMMC) and other eye by standard dose MMC (SDMMC). Then the patients were followed up to 6 months and refraction, Uncorrected Distant Visual Acuity (UCDVA), Best Corrected Distant Visual Acuity (BCDVA) and haze formation submitted in each postoperative exam. Results: The mean preoperative refraction in LDMMC eyes was -3.08 (SD 1.65) sphere and 0.92 (SD 0.88) cylinder. These values for SDMMC eyes were -3.25 (SD 1.80) sphere and 0.81 (SD 0.84) cylinder. Mean postoperative sphere in LDMMC group was -0.132 (SD 0.503) and -0.138 (SD 0.484) in 3 and 6 months after PRK. These results was -0.041 (SD 0.501) and -0.076 (SD 0.489) for SDMMC group. Mean postoperative cylinder 3 and 6 month after PRK was 0.435 (SD 0.218) and 0.423 (SD 0.255). In LDMMC group and 0.435 (SD 0.247) and 0.426 (SD 0.261) in SDMMC group. In third month 14 eyes in LDMMC group presented with grade 1 score of clinical haze. From these eyes only 2 still had this haze after 6 month. 7 eyes in SDMMC group had grade 1 clinical haze at third month- but no clinical haze was seen at the end of 6 th month. Conclusion: The results of the two doses of Mitomycin C were not significant. We suggest to use the lower dose to reduce its side effects

Short-term result of collagen crosslinking in pellucid marginal degeneration

Background: To evaluate effectiveness of collagen crosslinking in pellucid marginal degeneration patients. Materials and Methods: Twenty-one eyes of 15 patients treated by collagen crosslinking were enrolled in our non-controlled clinical trial study. After evaluation of patients about inclusion and exclusion criteria, preoperative examination was done and then patients underwent CXL procedure and seen 6 months after surgery for postoperative examinations. Results: Mean preoperative LogMar uncorrected visual acuity (UCVA) was 0.63 (SE = 0.08), and mean preoperative LogMar BCVA was 0.26 (SE = 0.04). At 6 months postoperative, mean LogMar UCVA was 0.59 (SE = 0.06) and mean LogMar BCVA was 0.19 (SE = 0.02). The non-parametric test (Wilcoxon) showed reduction of LogMar BCVA was significant (P value = 0.02), but reduction of LogMar UCVA was not significant (P value = 0.5). Mean preoperative K1 was 42.23 ± 2.85 and mean postoperative K1 significantly decreased to 41.68 ± 2.44 (P value = 0.008). Also, mean preoperative K2 was 48.39 ± 2.37 and mean postoperative K2 significantly reduced to 47.64 ± 2.16 (P value = 0.002). Conclusion: Most remarkable findings of our study were improvement of visual acuity and reduction K1 and K2 parameters. Stability of other values and absence of detectable change after study period implies halting of the progression of the disease. We suggest CXL can be useful for management of PMD, but we need more studies with larger sample size and longer follow up

Toric Intraocular Lens for Astigmatism Correction in Cataract Patients

Background: To assess the clinical consequences of AcrySof toric intraocular lens (IOL) and Hoya toric IOL implantation to correct preexisting corneal astigmatism in patients undergoing cataract surgery. Materials and Methods: In this study, we examined 55 eyes of 45 patients with at least 1.00 D corneal astigmatism who were scheduled for cataract surgery. After phacoemulsification, toric IOL was inserted and axis was aligned. We observed the patients' uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometry, manifest refraction, and IOL axis alignment 6 months after surgery. Results: After 6 months, the UDVA was 0.17 ± 0.17 logMAR in the AcrySof group and 0.17 ± 0.18 logMar in the Hoya group. More than 78% of eyes in the AcrySof group and 80% of eyes in the Hoya toric IOL achieved a UDVA of 20/40 or better. In the AcrySof group, the mean preoperative corneal astigmatism was 2.73 ± 0.92 D. The mean postoperative refractive astigmatism was 0.84 ± 0.63 D. In the Hoya group, the preoperative corneal astigmatism was 2.58 ± 0.76 D and the postoperative refractive astigmatism was 0.87 ± 0.66 D (P 0.05 for all). Conclusion: Implantation of AcrySof toric IOL and Hoya toric IOL was an effective way to correct preexisting corneal astigmatism in cataract surgery