NADP-dependent isocitrate dehydrogenase (NADP-ICDH) is one of the main sources of cellular reductant capacity in the form of NADPH. Although there is significant knowledge about the relevance of this enzyme during some physiological and stress processes, the available information about its involvement in fruit ripening is scarce. Using sweet green pepper (Capsicum annuum L.) fruits, a 50-75 % ammonium-sulfate-enriched protein fraction containing the NADP-ICDH activity allowed its biochemical characterization. The enzyme displayed a typical Michaelis-Menten kinetics and exhibited V and K values of 97 μUnits and 78 µM for isocitrate, and 92 μUnits and 46 µM for NADP. Three NADP-ICDH isozymes were identified by non-denaturing PAGE designated as NADP-ICDH I to III, each representing 33 %, 24 %, and 43 %, respectively, of the total activity. Based on our previous transcriptome (RNA-Seq), three CaICDH genes (CaNADP-ICDH1, CaNADP-ICDH2, and CaNADP-ICDH3) were identified in sweet pepper fruits encoding isozymes potentially distributed in the cytosol, cytosol/mitochondrion, and peroxisome, according to their percentage of identity with the Arabidopsis isozymes. The time-course expression analysis of these genes during different fruit ripening stages including green immature (G), breaking point (BP), and red ripe (R), and in fruits subjected to nitric oxide (NO) treatments, showed dissimilar expression patterns. During ripening from green to red fruits, CaNADP-ICDH1 and CaNADP-ICDH2 were upregulated but were negatively affected by NO; however, CaNADP-ICDH3 was downregulated during ripening but unaffected by NO treatment. Furthermore, during ripening, the NADP-ICDH activity increased in red ripe fruits whereas the NO gas treatment produced a significant inhibition. These findings provide, to our knowledge, the first characterization of the NADP-ICDH family in this non-climacteric fruit and suggest that NADP-ICDH must play an important role in maintaining the supply of NADPH during pepper fruit ripening and that NO partially modulates this NADPH-generating system.
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http://dx.doi.org/10.1016/j.plantsci.2024.112269 | DOI Listing |
Sci Rep
January 2025
Department of Botany, Government College Women University, Sialkot, Pakistan.
The phytochemical fingerprinting that add to the nutritional and nutraceutical value of the fruits during the ripening stages is beneficial for human consumption. Therefore, ripening-dependent changes in phytochemical content and antioxidant activities of mango (Mangifera indica L.) cultivar Dusehri at various ripening stages were evaluated.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, China.
A nuclear-localized cysteine desulfhydrase, LCD1, plays a crucial role in mediating endogenous hydrogen sulfide production in tomatoes. However, the mechanism underlying the nuclear localization of SlLCD1 is not yet fully understood. In this study, it was found that SlLCD1 specifically interacted with nuclear import receptor importin α3 (SlIMPA3).
View Article and Find Full Text PDFFront Plant Sci
December 2024
The Engineering Research Institute of Agriculture and Forestry, Ludong University, Yantai, China.
Abscisic acid (ABA) is a key hormone in plant growth and development, playing a central role in responses to various biotic and abiotic stresses as well as in fruit ripening. The present study examined the impact of ABA and nordihydroguaiaretic acid (NDGA) on various postharvest 'Docteur Jules Guyot' pear fruit characteristics, including firmness, pectinase activity, pectin content, volatile aromatic substances, and the expression of correlated genes. The results showed that ABA quickly reduced fruit firmness, increasing the activity of pectin degradation-related enzymes.
View Article and Find Full Text PDFNat Commun
December 2024
State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Fruit ripening is a highly-orchestrated process that requires the fine-tuning and precise control of gene expression, which is mainly governed by phytohormones, epigenetic modifiers, and transcription factors. How these intrinsic regulators coordinately modulate the ripening remains elusive. Here we report the identification and characterization of FvALKBH10B as an N-methyladenosine (mA) RNA demethylase necessary for the normal ripening of strawberry (Fragaria vesca) fruit.
View Article and Find Full Text PDFSci Rep
December 2024
Hangzhou Academy of Agricultural Sciences, 261 Zhusi Road, Zhuangtang Street, Hangzhou, 310024, Zhejiang, China.
This study determined the effects of the mycelium post-ripening time on the growth of Pleurotus geesteranus and the substrate metabolism. The characteristic indexes and timing reflecting the physiological maturity of P. geesteranus mycelium were identified to facilitate precise cultivation in factories.
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