This study aimed to examine the effect of modified atmosphere (MA) storage on the quality and storability of romaine lettuce. Whole and fresh-cut romaine lettuce were packaged with 1300; 10,000; 50,000; 100,000 cc m⁻²·day⁻¹·atm⁻¹ O₂ transmission rate (OTR) films and stored at 2 or 8 °C for 15 days. The respiration and ethylene production rates before pre-cooling were higher in fresh-cut lettuce than in whole romaine lettuce. The reduction in fresh weight for whole and fresh-cut romaine lettuce during storage was less than 0.5%. The CO₂ concentration was less than 2%, except for the 1300 cc treatment (at 8 °C for whole and fresh-cut lettuce) and 10,000 cc (in fresh-cut lettuce). At the end date of storage, the overall quality of the whole lettuce was good, the off-odor was lower in the 10,000 cc treatment, and the 50,000 cc treatment at 8 °C led to good overall quality in the fresh-cut lettuce. The chlorophyll content of the whole lettuce was maintained at a higher level in the treatment of 10,000 cc at 8 °C, while it was higher in the 50,000 cc treatments at 2 and 8 °C in the fresh-cut lettuce. Correlation and PCA confirmed that the main factors affecting the storability and quality of romaine lettuce were fresh weight loss rate, off-odor, and the concentration of CO₂. In addition, the storage characteristics of whole and fresh-cut lettuce were opposite to 0 in PC1 and PC2, indicating that the storage characteristics were different depending on the processing type.

Green asparagus is vulnerable to thrips that carry microorganisms and cause deterioration in quality. The effects of 60% CO₂ treatment, which is used to kill thrips, combined with perforated (P) or modified atmosphere (MA) packages during cold storage, on the sensory quality and physiological–biochemical characteristics of asparagus were investigated. MA packaging yielded an asparagus shelf-life five days longer than P packaging. The 60% CO₂ treatment for 48 h at 4 °C packaged with MA film (CO₂-48 h-4 °C-MA) showed a lower number of aerobic bacteria, yeast, and mold. Yellowing of asparagus was retarded, as shown by higher hue angle and chlorophyll content and lower chlorophyllase activity. Also, CO₂-48 h-4 °C-MA treatment inhibited the reduction of soluble solids content in asparagus. Likewise, all high CO₂ treatments showed lower electrolyte leakage (EL), with CO₂-48 h-4 °C-MA demonstrating the minimum EL. The effectiveness of high CO₂ on maintaining sensory qualities was observed, with a score higher than 3.0. In conclusion, CO₂-48 h-4 °C-MA treatment during cold storage was effective for maintaining post-harvest sensory qualities and physiological–biological traits of asparagus, and provided strong inhibition of microflora growth during the storage period.

The S1fa transcription factor is part of a small family involved in plant growth and development and abiotic stress tolerance. However, the roles of the S1fa genes in abiotic stress tolerance in Chinese cabbage are still unclear. In this study, four S1fa genes in the Chinese cabbage genome were identified and characterized for abiotic stress tolerance. Tissue-specific expression analysis suggested that three of these four S1fa genes were expressed in all tissues of Chinese cabbage, while Bra006994 was only expressed in the silique. Under Hg and Cd stresses, the S1fa genes were significantly expressed but were downregulated under NaCl stresses. The Bra034084 and Bra029784 overexpressing yeast cells exhibited high sensitivity to NaCl stresses, which led to slower growth compared with the wild type yeast cells (EV) under 1 M NaCl stress. In addition, the growth curve of the Bra034084 and Bra029784 overexpressing cells shows that the optical density was reduced significantly under salt stresses. The activities of the antioxidant enzymes, SOD, POD and CAT, were decreased, and the MDA, H₂O₂ and O₂⁻ contents were increased under salt stresses. The expression levels of cell wall biosynthesis genes Ccw14p, Cha1p, Cwp2p, Sed1p, Rlm1p, Rom2p, Mkk1p, Hsp12p, Mkk2p, Sdp1p and YLR194c were significantly enhanced, while Bck1p, and Ptc1p were downregulated under salt stresses. These results suggest that the Bra034084 and Bra029784 genes regulate cell wall biosynthesis and the defense regulatory system under salt stresses. These findings provide a fundamental basis for the further investigation of crop genetic modification to improve crop production and abiotic stress tolerance in Chinese cabbage.

Chinese cabbage tipburn is characterized by the formation of necrotic lesions on the margin of leaves, including on the insides of the leafy head. This physiological disorder is associated with a localized calcium deficiency during leaf development. However, little information is available regarding the molecular mechanisms governing Ca-deficiency-triggered tipburn. This study comprehensively analysed the transcriptomic comparison between control and calcium treatments (CK and 0 mM Ca) in Chinese cabbage to determine its molecular mechanism in tipburn. Our analysis identified that the most enriched gene ontology (GO) categories are photosynthesis, thylakoid and cofactor binding. Moreover, the KEGG pathway was most enriched in photosynthesis, carbon metabolism and carbon fixation. We also analyzed the co-expression network by functional categories and identified ten critical hub differentially expressed genes (DEGs) in each gene regulatory network (GRN). These DEGs might involve abiotic stresses, developmental processes, cell wall metabolism, calcium distribution, transcription factors, plant hormone biosynthesis and signal transduction pathways. Under calcium deficiency, CNX1, calmodulin-binding proteins and CMLs family proteins were downregulated compared to CK. In addition, plant hormones such as GA, JA, BR, Auxin and ABA biosynthesis pathways genes were downregulated under calcium treatment. Likewise, HATs, ARLs and TCP transcription factors were reported as inactive under calcium deficiency, and potentially involved in the developmental process. This work explores the specific DEGs’ significantly different expression levels in 0 mM Ca and the control involved in plant hormones, cell wall developments, a light response such as chlorophylls and photosynthesis, transport metabolism and defence mechanism and redox. Our results provide critical evidence of the potential roles of the calcium signal transduction pathway and candidate genes governing Ca-deficiency-triggered tipburn in Chinese cabbage.

This research investigated the effects of continuous elevated CO₂ (20%, (v/v)) application or a 3 day CO₂ pretreatment followed by modified atmosphere (MA) or micro-perforated (MP) packaging on the postharvest quality of asparagus. The combination of CO₂ pretreatment with MA packaging (Pre-MA) inhibited the yellowing of asparagus and fresh weight loss (FWL), whereas stem firmness slightly increased with all elevated CO₂ treatments. CO₂ pretreatments increased antioxidant activity in the stem, but not in the tip, in contrast to the continuous flow CO₂ (Flow-CO₂) treatment. The phenolic and flavonoid contents increased in the elevated CO₂ pretreatments and Flow-CO₂ treatment. The elevated CO₂ treatments, especially Flow-CO₂, inhibited the development of microorganisms, and the treated asparagus did not decay. Pre-MA and Flow-CO₂ treatments were more effective in maintaining the visual quality and retarding the off-odor of asparagus. Furthermore, significant correlations between sensory quality characteristics and physiological-biochemical attributes were recognized; three principal components were extracted and they explained 86.4% of asparagus characteristics. The results confirmed the importance of visual quality, off-odor, firmness, color parameters, SSC and total phenolic content. In conclusion, elevated CO₂ pretreatment followed by MA packaging (Pre-MA) was beneficial for extending asparagus cold storage shelf life, and Flow-CO₂ was the best treatment for inhibiting postharvest decay.

Leaf morphogenesis is governed by a tightly integrated regulatory network centered on auxin, which operates through a sequential axis of synthesis, transport, and signal transduction. This review elucidates how pivotal molecular hubs previously identified in this regulatory network, including biosynthetic enzymes, polar transporters, and auxin response factors, interconnect through dynamic feedback mechanisms to orchestrate leaf initiation, polarity establishment, and the determination of its final size and shape. Notably, recent breakthroughs are transforming the field: the re-evaluation of established pathways like indole-3-acetaldoxime (IAOx), whose direct contribution to auxin pools is under scrutiny, hinting at the existence of undiscovered enzymes or alternative metabolic branches and the paradigm-shifting discovery that cAMP functions as a second messenger produced by Transport Inhibitor Resistant 1/Auxin signaling F-box (TIR1/AFB) receptors, which directly activates Auxin Response Factor (ARF)-mediated transcription. These foundational mechanistic insights provide the critical groundwork for application. Key network nodes—such as PIN-FORMED (PIN) transporters and YUCCA (YUC) flavin-containing monooxygenases—are now validated targets for crop improvement. Consequently, the elucidated network serves as a blueprint for rationally designing crop architecture.