Insertion of the β-ketoacyl-CoA synthase MdKCS2 promoter segment causes wax biosynthesis difference in apple peel.

Cuticular wax is essential for fruit to maintain moisture. Although the wax content of peel surface in apple (Malus spp.) varies, the detailed molecular mechanism remains unclear.

Transcription factors PuNAC37/PuWRKY74 and E3 ubiquitin ligase PuRDUF2 inhibit volatile ester synthesis in 'Nanguo' pear.

As major contributors to flavor in many fruit species, volatile esters are useful for investigating the regulation of the biosynthesis pathways of volatile aroma compounds in plants. Ethylene promotes the biosynthesis of volatile esters during fruit storage while accelerating fruit ripening; thus, the ethylene perception inhibitor 1-methylcyclopropene (1-MCP) is employed to prolong the shelf life of fruits. However, the mechanisms by which 1-MCP regulates volatiles synthesis remain unclear.

The Ca-MdCRF4-MdWRKY9 module negatively affects apple fruit watercore formation by suppressing the transcription of MdSOT2.

Watercore is a common physiological disease of Rosaceae plants, such as apples (Malus domestica), usually occurring during fruit ripening. Apple fruit with watercore symptoms is prone to browning and rotting, thus losing commercial viability. Sorbitol and calcium ions are considered key factors affecting watercore occurrence in apples.

The chemical recognition of hydrogen fluoride via BN nanocage: quantum chemical approach.

Context: Ab initio calculations were employed in this investigation to scrutinize the adsorption characteristics of a linear chain (HF)n on a BN nanocage (BN), wherein the chain lengths varied (n = 1, 2, 3, and 4). The overarching aim was to assess the efficiency of this setup in detecting and adhering to (HF)n under both liquid and gaseous scenarios. This study encompassed an array of aspects, encompassing adsorption energy, optimal configuration determination, work function analysis, and charge exchange assessment.

Genome-wide identification of CXE and PuCXE15 functions in the catabolism of volatile ester in 'Nanguo' pear fruit.

Volatile esters are the main aromatic components that affect consumer sensory preferences. Aroma is a crucial characteristic of the 'Nanguo' pear (Pyrus ussriensis Maxim). Carboxylesterases (CXEs) are positively correlated with the catabolism of volatile esters in peaches; however, the mechanism of action of CXE family members in 'Nanguo' pear is poorly understood.

Ethylene enhances MdMAPK3-mediated phosphorylation of MdNAC72 to promote apple fruit softening.

The phytohormone ethylene plays an important role in promoting the softening of climacteric fruits, such as apples (Malus domestica); however, important aspects of the underlying regulatory mechanisms are not well understood. In this study, we identified apple MITOGEN-ACTIVATED PROTEIN KINASE 3 (MdMAPK3) as an important positive regulator of ethylene-induced apple fruit softening during storage. Specifically, we show that MdMAPK3 interacts with and phosphorylates the transcription factor NAM-ATAF1/2-CUC2 72 (MdNAC72), which functions as a transcriptional repressor of the cell wall degradation-related gene POLYGALACTURONASE1 (MdPG1).

The mechanisms underpinning anthocyanin accumulation in a red-skinned bud sport in pear (Pyrus ussuriensis).

In our study, we demonstrated that histone acetylation promotes anthocyanin accumulation in pears by affecting the expression of key genes. Color is an important trait of horticultural plants, and the anthocyanin content directly affects the nutritional value and commercial value of colored fruits. Therefore, it is important for fruit breeding to cultivate new varieties with bright colors.

Recent advances in epigenetic triggering of climacteric fruit ripening.

During ripening, fleshy fruits undergo irreversible changes in color, texture, sugar content, aroma, and flavor to appeal to seed-dispersal vectors. The onset of climacteric fruit ripening is accompanied by an ethylene burst. Understanding the factors triggering this ethylene burst is important for manipulating climacteric fruit ripening.

Monitoring of COS, SO, HS, and CS gases by AlP nanoclusters: a DFT inspection.

Through utilizing density functional theory (DFT), the current work investigates the potential uses of AlP fullerene for detecting CS, HS, SO, and COS. The interaction order for the stability of these gases was SO > HS > COS > CS. The moment of electric dipole and molecules' adsorption energy seems correlated.

Exogenous Ca2+ promotes transcription factor phosphorylation to suppress ethylene biosynthesis in apple.

Ethylene biosynthesis in apple (Malus domestica) fruit can be suppressed by calcium ions (Ca2+) during storage; however, the underlying mechanisms are unclear. In this study, we identified the apple transcription factor MCM1-AGAMOUS-DEFICIENS-SRF5 (MdMADS5), which functions as a transcriptional activator of the ethylene biosynthesis-related gene 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID SYNTHASE1 (MdACS1), a partner of the calcium sensor CALCIUM-DEPENDENT PROTEIN KINASES7 (MdCDPK7). Ca2+ promoted the MdCDPK7-mediated phosphorylation of MdMADS5, which resulted in the degradation of MdMADS5 via the 26S proteasome pathway.

PuWRKY31 affects ethylene production in response to sucrose signal in pear fruit.

The ripening of climacteric fruits is mainly controlled by the plant hormone ethylene. The regulatory effect of sucrose on ethylene biosynthesis in fruits remains unclear. Here we examined ethylene production in two Ussurian pear () varieties, 'Nanguo' (NG) pear and its bud sport variety (BNG), which has a higher sucrose content.

The molecular mechanism on suppression of climacteric fruit ripening with postharvest wax coating treatment transcriptome.

Wax coating is an important means to maintain fruit quality and extend fruit shelf life, especially for climacteric fruits, such as apples (). Here, we found that wax coating could inhibit ethylene production, chlorophyll degradation, and carotenoid synthesis, but the molecular mechanism remains unclear. The regulatory mechanism of wax coating on apple fruit ripening was determined by subjecting wax-treated apple fruits to transcriptome analysis.

The Transcription Repressor Regulates Cell and Fruit Size in Apple Fruit.

Auxin plays an important role in regulating plant development, and () is a type of auxin-responsive gene and plays an important role in auxin signaling; to date, although 29 Aux/IAA proteins have been reported in , only parts of the family gene functions have been identified. We previously reported that a bud sport of 'Longfeng' (LF) apple (), named 'Grand longfeng' (GLF), which showed a larger fruit size than LF, has lower expression of . In this study, we identified the function of the gene in apple fruit size difference using -mediated genetic transformation.

Integrated metabolome and transcriptome analysis of the regulatory network of volatile ester formation during fruit ripening in pear.

'Nanguo' pear (Pyrus ussuriensis Maxim.) is a typical climacteric fruit with an attractive aroma after postharvest ripening. Esters are the key volatile compounds determining the typical aroma formation.

NUCLEOCYTOPLASMIC shuttling of ETHYLENE RESPONSE FACTOR 5 mediated by nitric oxide suppresses ethylene biosynthesis in apple fruit.

Nitric oxide (NO) is known to modulate the action of several phytohormones. This includes the gaseous hormone ethylene, but the molecular mechanisms underlying the effect of NO on ethylene biosynthesis are unclear. Here, we observed a decrease in endogenous NO abundance during apple (Malus domestica) fruit development and exogenous treatment of apple fruit with a NO donor suppressed ethylene production, suggesting that NO is a ripening suppressor.

Recent Advances in Phytohormone Regulation of Apple-Fruit Ripening.

Apple () is, globally, one of the largest fruits in terms of cultivated area and yield. Apple fruit is generally marketed after storage, which is of great significance for regulating the market supply in the off-season of fruit production. Apple-fruit ripening, which culminates in desirable changes in structural and textural properties, is governed by a complex regulatory network.

Ethylene-activated MdPUB24 mediates ubiquitination of MdBEL7 to promote chlorophyll degradation in apple fruit.

Chlorophyll (Chl) degradation is a natural phenomenon that occurs during ripening in many fleshy fruit species, and also during fruit storage. The plant hormone ethylene is a key factor in promoting Chl degradation during fruit storage, but the mechanisms involved in this induction are largely unknown. In this study, an apple (Malus domestica) BEL1-LIKE HOMEODOMAIN transcription factor 7 (MdBEL7), potentially functioning as a transcriptional repressor of the Chl catabolic genes (CCGs), including MdCLH, MdPPH2 and MdRCCR2, was identified as a partner of the ethylene-activated U-box type E3 ubiquitin ligase MdPUB24 in a yeast library screen.

The mechanism for brassinosteroids suppressing climacteric fruit ripening.

The plant hormone ethylene is important for the ripening of climacteric fruit, such as pear (Pyrus ussuriensis), and the brassinosteroid (BR) class of phytohormones affects ethylene biosynthesis during ripening via an unknown molecular mechanism. Here, we observed that exogenous BR treatment suppressed ethylene production and delayed fruit ripening, whereas treatment with a BR biosynthesis inhibitor promoted ethylene production and accelerated fruit ripening in pear, suggesting BR is a ripening suppressor. The expression of the transcription factor BRASSINAZOLE-RESISTANT 1PuBZR1 was enhanced by BR treatment during pear fruit ripening.

Endogenous Auxin Content Contributes to Larger Size of Apple Fruit.

Fruit size is an important economic trait that is controlled by multiple genes. However, the regulatory mechanism for fruit size remains poorly understood. A bud sport variety of "Longfeng" (LF) apple () was identified and named "Grand Longfeng" (GLF).

Auxin-activated MdARF5 induces the expression of ethylene biosynthetic genes to initiate apple fruit ripening.

The gaseous plant hormone ethylene induces the ripening of climacteric fruit, including apple (Malus domestica). Another phytohormone, auxin, is known to promote ethylene production in many horticultural crops, but the regulatory mechanism remains unclear. Here, we found that auxin application induces ethylene production in apple fruit before the stage of commercial harvest, when they are not otherwise capable of ripening naturally.

Histone Acetylation at the Promoter for the Transcription Factor PuWRKY31 Affects Sucrose Accumulation in Pear Fruit.

Sugar content is an important trait of fleshy fruit, and elevating Suc levels is a major goal in horticultural crop breeding. Here, we examined the sugar content in two varieties of the Ussurian pear (), 'Nanguo' (NG) and its bud sport (BNG), and we found that Suc content was higher in BNG fruit than in NG fruit. We compared the transcriptomes of the two varieties using RNA sequencing and identified a () gene, , expressed at higher levels in BNG fruit.

Enhancement of apple coloration using jasmonate treatment without sacrificing storage potential.

Apple coloration is very important for most cultivars. The application of jasmonate can effectively enhance the coloration of apple fruit, but it might ruin the fruit's storage potential. Here, we report that applying methyl jasmonate on apple fruit 3 weeks before commercial harvest not only enhanced the fruit coloration but also did not affect its storage potential.