Early Fruit Research Articles

Absorption and translocation to fruit for cesium applied on apple tree leaf surface.

We investigated the behavior of stable Cs+ ions contained in droplets applied directly on the leaf surfaces of plumleaf crab apple trees (2-3years old Malus domestica 'Alps Otome') at three different fruit growing stages: before bearing fruit, early fruit development and late fruit development stages. Most of the Cs was rapidly transferred from the leaf surfaces into the applied leaves after application, and then gradually transferred to the fruit through the branches. The mean proportion of Cs transferred to fruit by harvest time ranged from 11 to 30% not directly depending on the fruit growing stages. Cs absorption from leaf surfaces was faster at early and late fruit development stages than before bearing fruit stage, and Cs transfer from leaf surfaces to the fruit was faster as the fruit growing stage progressed. To describe the transfer of Cs, we constructed a compartment model using the datasets of obtained for each fruit growing stage. However, it did not well reproduce the measured values, showing that further studies are necessary.

Genome-Wide Identification of UGT Genes and Analysis of Their Expression Profiles During Fruit Development in Walnut (Juglans regia L.)

Walnut (Juglans regia L.) possesses the ability to prevent coronary heart disease and promote cardiovascular health. This ability can be attributed to their rich content of polyphenols, particularly flavonoids. The biosynthesis of flavonoids is reliant on the catalytic activity of uridine diphosphate glycosyltransferase (UGT). However, the identification of UGTs in walnut has not been reported. In the current study, a total of 124 UGT genes containing the PSPG box were identified from the walnut genome. Based on phylogenetic analysis, the 124 UGTs could be classified into 16 distinct groups, which exhibited an uneven distribution across the 16 chromosomes. Subcellular localization prediction analysis revealed that approximately 78.23% of walnut UGT proteins were predominantly localized in the cytoplasmic compartment. Furthermore, motif annotation confirmed that motifs 1, 2, and 3 represented conserved structural features within UGT proteins, while interestingly, around 56.5% of walnut UGT members lacked introns. Through the analysis of promoter cis-regulatory elements, it was revealed that JrUGTs are involved in photoresponse, hormonal regulation, and other physiological responses. In conjunction with transcriptome analysis and quantitative expression, approximately 39% of UGT genes in walnut exhibited high expression levels during early fruit development. Correlation analysis between UGT genes’ expression and phenolic content in walnut indicated that JrUGT6, JrUGT38, JrUGT39, JrUGT58, JrUGT69, JrUGT75, and JrUGT82 might be involved in phenolic biosynthesis in walnut. This comprehensive study provides an overview of the UGT genes in walnut, serving as a valuable reference and theoretical foundation for further investigations into the biological functions of JrUGTs in flavonoid biosynthesis.

Soil-Mulching Treatment Enhances the Content of Stilbene in Grape Berries: A Transcriptomic and Metabolomic Analysis

Soil mulching is a useful agronomic practice that promotes early fruit maturation and affects fruit quality. However, the regulatory mechanism of fruit metabolites under soil-mulching treatments remains unknown. In this study, variations in the gene sets and metabolites of grape berries after mulching (rice straw + felt + plastic film) using transcriptome and metagenomic sequencing were investigated. The results of the cluster analysis and orthogonal projection to latent structures discriminant analysis of the metabolites showed a difference between the mulching and control groups, as did the principal component analysis results for the transcriptome. In total, 36 differentially expressed metabolites were identified, of which 10 (resveratrol, ampelopsin F, piceid, 3,4′-dihydroxy-5-methoxystilbene, ε-viniferin, trans resveratrol, epsilon-viniferin, 3′-hydroxypterostilbene, 1-methyl-resveratrol, and pterostil-bene) were stilbenes. Their content increased after mulching, indicating that stilbene synthase activity increased after mulching. The weighted gene co-expression network analysis revealed that the turquoise and blue modules were positively and negatively related to stilbene compounds. The network analysis identified two seed genes (VIT_09s0054g00610, VIT_13s0156g00260) and two transcription factors (VIT_13s0156g00260, VIT_02s0025g04590). Overall, soil mulching promoted the accumulation of stilbene compounds in grapes, and the results provided key genetic information for further studies.

Toxicity of paclobutrazol-based pesticide on Lactuca sativa L.: germination, seedling development, and DNA damage.

Paclobutrazol, a fungicide of the triazole class, is widely used as an inducer of early flowering and fruiting by inhibiting gibberellin formation. However, biological assays using model organisms to evaluate their cytogenotoxic and mutagenic potential are still scarce. Therefore, this study aimed to investigate the effects of the commercial product Cultar® 250 SC (CP) and the pure substance (PBZ) on the germination and initial seedling development of Lactuca sativa L. (lettuce), in addition to evaluating the effects of CP on the mitotic activity and DNA, as we believe that PBZ has a greater toxic potential than CP on seed germination, and that the latter has cytogenotoxic and mutagenic effects on L. sativa. Lettuce seeds treated with CP and with PBZ in the doses of 0.25, 0.50, 1, 1.5, and 2g L-1 showed significant reductions in germination rate, as well the CP reduced the root and initial development seedling development. PBZ showed greater inhibition of germination compared to CP. In direct exposure to PBZ, there was not sufficient seedling development for analysis, while in discontinuous treatment, there was inhibition of root growth (except for doses of 0.25 and 0.50g L-1) and in the development of the aerial part. While no mitodepressive effect was observed in meristematic cells treated with CP, increased frequencies of chromosomal alterations, including condensed nuclei and micronuclei, were evident in both meristematic cells and the F1 region. The Comet assay further demonstrated higher levels of DNA damage at higher paclobutrazol doses, supporting the findings of increased micronucleus frequencies. Consequently, it can be concluded that the CP exhibits greater toxicity towards seed germination compared to lettuce seedlings, and PBZ has a greater toxic potential than CP in relation to these parameters. However, the impact of CP on seedlings was relatively minimal, as evidenced by their limited effects on development, cell proliferation, and DNA, suggesting a slight toxicity of this agent. Therefore, we infer that Cultar® 250 SC should be used with caution. Thus, this study emphasizes the importance of employing joint analyses to better elucidate and correlate the mechanisms of action of potentially toxic substances. Furthermore, it provides a basis for discussing the application of Cultar® 250 SC and seeking more sustainable alternatives in food production.

A logistic model for precise tomato fruit-growth prediction based on diameter-time evolution

Monitoring tomato fruit growth in large greenhouse environments is crucial for estimating harvest volume and maximising labour efficiency. Mathematical modelling is commonly used to characterise crop and fruit growth and to understand crop responses to environmental influences. This study presents a logistic approach for estimating tomato fruit maturity based on fruit diameter. A set of logistic models were evaluated, and their precision and ability to forecast tomato fruit growth were analysed. Non-linear least square regression was used to fit each model to individual tomato fruits from a sample of over 600 fruits of two species (small and large fruit-bearing tomatoes) grown within one year. The focus was on fruit diameter and the necessary measurement precision for fruit maturity estimation. Low-dispersion variables were identified within our logistic model functions, and fruit species-specific model parameters were determined. Furthermore, we reduced the number of regression variables by identifying parameters of low variance. This allowed for high prediction precision (>80%) at the early fruit maturity stages (<30%). The fruit diameter data were collected manually using a caliper. Our results establish an upper limit for the measurement precision of automated fruit size estimation approaches utilising photogrammetry, with an optical range of 98% for 3 mm and 90% for 5 mm precision.

Sink Strength Dynamics Based on Potential Growth and Carbohydrate Accumulation in Strawberry Fruit

Fruit size and sugar content are key determinants of fruit quality, influenced by environmental factors and agronomic practices and sink strength provided by the genetic potential. Strawberry (Fragaria ×ananassa) produces fruits arranged in inflorescences, whose growth is affected by carbon competition between them. The competitive ability is termed as sink strength, which can be quantified as the potential growth rate under sufficient resource supply and/or no carbon competition among sinks, referred to as non-limiting conditions. Most previous studies did not observe potential growth, thereby failing to adequately evaluate sink strength and to assess the influence of environmental factors and agronomic practices on fruit growth. This study aimed to investigate the potential growth of strawberry fruits and analyze its sink strength dynamics. Non-limiting conditions were established by removing flowers to one fruit per inflorescence in a greenhouse experiment with plants grown in soil and given water and nutrients through drip irrigation. Fruits were harvested every 5 days from 5 to 55 days after anthesis (DAA), measuring the size, weight, and concentrations of major soluble carbohydrates in strawberry (sucrose, glucose, and fructose) and starch. Sink strength was represented by absolute growth rate based on fruit weight, and its components, sink size and sink activity, were represented by weight and relative growth rate, respectively. Fruit volume and weight showed a gradual linear increase at 5 DAA and then rapidly increased, following a single sigmoid curve between 30 and 55 DAA. Fruits primarily accumulated glucose and fructose during early growth, shifting to sucrose after 35 DAA. Starch concentration peaked at 5 DAA and then exponentially decreased. Sink strength exhibited a single peak between 40 DAA and 45 DAA. Sink strength gradually increased with sink size until 30 DAA, whereas sink activity significantly decreased until 30 DAA. Thereafter, sink strength and sink activity exhibited a peak, whereas sink size continued to increase. These results suggest that the major determinant of sink strength was sink size during early fruit growth, shifting to sink activity during late growth.

FBSM: Foveabox-based boundary-aware segmentation method for green apples in natural orchards

Image segmentation of target fruits is an essential part of machine vision systems, aiming to facilitate more accurate early fruit measurement and machine harvesting in natural orchard environments. Given that instance-level pooling and down-sampling operations in conventional segmentation models often lead to the loss of detailed information, resulting in coarse partitioning masks, we endeavor to restore the boundary information of the masks. To achieve high-quality fruit segmentation with clear boundaries and refined masks, a Foveabox-based boundary-aware segmentation model (FBSM) is constructed by adding a multi-stage mask prediction head incorporating fine-grained features to the anchor-free detection model FoveaBox to realize accurate segmentation of green apple fruits. At each stage, a bi-layer fusion structure (BFS) is employed to fully fuse the fine-grained features in a double-fusion manner to guide the subsequent instance mask prediction. Finally, the boundary recovery module (BRM) is leveraged to recover the lost boundary detail information and obtain more accurate boundaries for the continuous optimization process of the fruit instance mask. Experimental results demonstrate that the proposed FBSM model achieves a mean average precision (mAP) of 60.7 % for green apple instance segmentation in unstructured natural orchard environments, surpassing traditional instance segmentation models. Moreover, it enhances base model detection accuracy by 1.3 % while striking a better balance between detection and segmentation performance.

Mapping and transcriptomic profiling reveal that the KNAT6 gene is involved in the dark green peel colour of mature pumpkin fruit (Cucurbita maxima L.).

We identified a 580bp deletion of CmaKNAT6 coding region influences peel colour of mature Cucurbita maxima fruit. Peel colour is an important agronomic characteristic affecting commodity quality in Cucurbit plants. Genetic mapping of fruit peel colour promotes molecular breeding and provides an important basis for understanding the regulatory mechanism in Cucurbit plants. In the present study, the Cucurbita maxima inbred line '9-6' which has a grey peel colour and 'U3-3-44' which has a dark green peel colour in the mature fruit stage, were used as plant materials. At 5-40days after pollination (DAP), the contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids in the 'U3-3-44' peels were significantly greater than those in the '9-6' peels. In the epicarp of the '9-6' mature fruit, the presence of nonpigmented cell layers and few chloroplasts in each cell in the pigmented layers were observed. Six generations derived by crossing '9-6' and 'U3-3-44' were constructed, and the dark green peel was found to be controlled by a single dominant locus, which was named CmaMg (mature green peel). Through bulked-segregant analysis sequencing (BSA-seq) and insertion-deletion (InDel) markers, CmaMg was mapped to a region of approximately 449.51kb on chromosome 11 using 177 F2 individuals. Additionally, 1703 F2 plants were used for fine mapping to compress the candidate interval to a region of 32.34kb. Five coding genes were in this region, and CmaCh11G000900 was identified as a promising candidate gene according to the reported function, sequence alignment, and expression analyses. CmaCh11G000900 (CmaKNAT6) encodes the homeobox protein knotted-1-like 6 and contains 4 conserved domains. CmaKNAT6 of '9-6' had a 580bp deletion, leading to premature transcriptional termination. The expression of CmaKNAT6 tended to increase sharply during the early fruit development stage but decrease gradually during the late period of fruit development. Allelic diversity analysis of pumpkin germplasm resources indicated that the 580bp deletion in the of CmaKNAT6 coding region was associated with peel colour. Subcellular localization analysis indicated that CmaKNAT6 is a nuclear protein. Transcriptomic analysis of the inbred lines '9-6' and 'U3-3-44' indicated that genes involved in chlorophyll biosynthesis were more enriched in 'U3-3-44' than in '9-6'. Additionally, the expression of transcription factor genes that positively regulate chlorophyll synthesis and light signal transduction pathways was upregulated in 'U3-3-44'. These results lay a foundation for further studies on the genetic mechanism underlying peel colour and for optimizing peel colour-based breeding strategies for C. maxima.

Loss-of-function mutation in anthocyanidin reductase activates the anthocyanin synthesis pathway in strawberry

Fruit color substantially affects consumer preferences, with darker red strawberries being economically more valuable due to their higher anthocyanin content. However, the molecular basis for the dark red coloration remains unclear. Through screening of an ethyl methanesulfonate mutant library, we identified a rg418 mutant, that demonstrated anthocyanin accumulation during early fruit development stages. Furthermore, the ripening fruits of this mutant had higher anthocyanin content than wild-type (WT) fruits. An analysis of flavonoid content in WT and rg418 mutant fruits revealed substantial changes in metabolic fluxes, with the mutant exhibiting increased levels of anthocyanins and flavonols and decreased levels of proanthocyanidins. Bulked sergeant analysis sequencing indicated that the mutant gene was anthocyanidin reductase (ANR), a key gene in the proanthocyanidin synthesis pathway. Furthermore, transcriptome sequencing revealed the increased expression of MYB105 during the early development stage of mutant fruits, which promoted the expression of UFGT (UDP-glucose flavonoid 3-O-glucosyltransferase), a key gene involved in anthocyanin synthesis, thus substantially enhancing the anthocyanin content in the mutant fruits. Additionally, mutating ANR in a white-fruited strawberry variant (myb10 mutant) resulted in appealing pink-colored fruits, suggesting the diverse roles of ANR in fruit color regulation. Our study provides valuable theoretical insights for improving strawberry fruit color.

Урожайность гибридов смородины черной в Центральной Якутии

Abstract. A study was carried out of the yield and large-fruited original material of black currant in a breeding nursery in the conditions of Central Yakutia. The purpose is to identify sources of high yield and large-fruited black currant hybrids for use in breeding. The objectives of the study included high-yielding hybrids of black currant to carry out crop accounting and identify; determine the mass of berries in hybrids and select sources of large fruit. Methods. The research was carried out according to the generally accepted methodology “Program and methodology for the selection of fruit, berry and nut crops” (Oryol, 1995). Scientific novelty. For the first time, new sources of black currant productivity have been identified for breeding in Yakutia. Results. In the breeding nursery, 10 sources of high yield (more than 10 t/ha) and 4 sources of large-fruited black currant hybrids from various genetic groups were selected. Among them, the hybrid 3-7-18 (Podarok Kuzioru × Khara Kytalyk), a derivative of three subspecies of black currant and low-flowering currant with a yield of 18.9 t/ha, is distinguished by the characteristics of early fruiting, high and stable yield. Of 4 black currant hybrids - 3-19-18 (Podarok Kuzioru × Myuryuchana), 3-2-18 (Podarok Kuzioru × Khara Kytalyk), 2-18-18 (Podarok Kuzioru × Yakutskaya) and 1-17-18 (Ksyusha × Yakutskaya) was characteristic large fruiting. The weight of 1 berry ranged from 1.53 to 1.70 g. A negative relationship was revealed between the indicators of yield and large-fruited black currant (r = –0.47), as a result of mathematical processing of experimental data The identified sources of high yield and large fruit will be used in the selection of black currants in Central Yakutia to create new source material and further study them according to a set of traits.

Tissue Culture in Banana Cultivation: A Review of its Impact on Disease Management, Yield Improvement, and Sustainable Production

In several tropical and subtropical areas, bananas (Musa spp.) are an important food source and commercial crop. Disease transmission and production uncertainty are common problems with traditional propagation techniques such as suckers. By supplying consistent, high-quality, and disease-free planting material, tissue culture, known as micro propagation, represents a potential alternative. The application of tissue culture has greatly enhanced disease management in banana cultivation. Reducing the incidence of ailments like Fusarium wilt, bacterial wilt, and Banana Bunchy Top Virus (BBTV), pathogen-free plantlets are grown in controlled conditions. This strategy lessens the demand for artificial fertilizers while also promoting healthier crops and lessening the impact on the environment. Micropropagated banana plants demonstrated consistent growth, early fruiting, and increased yield in contrast to conventionally propagated plants. Tissue-cultured plants exhibit strong development and genetic uniformity, which contribute to these advantages and more consistent and dependable harvests. By promoting efficient land use and reducing the need for chemical inputs, tissue culture enhances sustainability in the production of bananas. The growing demand for bananas may be met without requiring the increase of agricultural land thanks to tissue culture techniques, which enable the large-scale production of enhanced banana cultivars at a quick rate. Furthermore, using planting material free of disease lowers input costs and crop losses, supporting more environmentally friendly farming methods.

Evaluation of culture filtrate of Trichoderma isolates with potential to induce Fusarium wilt resistance and promote early flower and fruit development in tomato

Evaluation of culture filtrate of Trichoderma isolates with potential to induce Fusarium wilt resistance and promote early flower and fruit development in tomato

Local Field-Scale Winter Wheat Yield Prediction Using VENµS Satellite Imagery and Machine Learning Techniques

Reliable and accurate crop yield prediction at the field scale is critical for meeting the global demand for reliable food sources. In this study, we tested the viability of VENμS satellite data as an alternative to other popular and publicly available multispectral satellite data to predict winter wheat yield and produce a yield prediction map for a field located in southwestern Ontario, Canada, in 2020. Random forest (RF) and support vector regression (SVR) were the two machine learning techniques employed. Our results indicate that machine learning models paired with vegetation indices (VIs) derived from VENμS imagery can accurately predict winter wheat yield 1~2 months prior to harvest, with the most accurate predictions achieved during the early fruit development stage. While both machine learning approaches were viable, SVR produced the most accurate prediction with an R2 of 0.86 and an RMSE of 0.3925 t/ha using data collected from tillering to the early fruit development stage. NDRE-1, NDRE-2, and REP from various growth stages were ranked among the top seven variables in terms of importance for the prediction. These findings provide valuable insights into using high-resolution satellites as tools for non-destructive yield potential analysis.

Three-dimensional reconstruction of Late Miocene Trapa from eastern Zhejiang Province, China: Insights into its phytogeography and evolution

Abundant plant fossils were found in the Upper Miocene Shengxian Formation, eastern Zhejiang Province, China, among which Trapa belongs to a dominant population. The fossil fruits of Trapa were well preserved with abundant details. However, due to compaction during fossilization, Trapa fruits were often flattened, leading to the loss of some characteristic features. Thereby, a bias in taxonomic and phylogenetic studies would occur when such studies were based on these fruit fossils. In this study, we present the first quantitative three-dimensional reconstruction of compressed Trapa fruit fossils to restore their original morphology prior to burial. This approach provides a novel perspective for the identification and classification of compressed fruit fossils. The three-dimensional reconstruction of Trapa fruit fossils enabled accurate comparisons with extant species. We subsequently identified it as a new species, named Traparadiatiformis L. Xiao sp. nov., revealing differences from previously known taxa of Trapa. Importantly, our comparison suggests that the long lower horns and residual stalk may represent inherent characteristics of early Trapa fruits. However, these traits gradually degenerated during fruit evolution, resulting in morphological simplification during geological time. T. radiatiformis with primitive features exhibits good resemblance to Trapanatans fruit characteristics, which means it may be an ancestor of T. natans. We summarize the palaeogeographic distribution of fossil Trapa using previously published literature and demonstrate that the genus was most prosperous in the Miocene and exhibited the same distribution as that at present. Additionally, through detailed morphological comparisons between Trapa and Hemitrapa fruits, along with phylogenetic analysis within the Primotrapa genus itself, we propose a homology between Trapa and Hemitrapa, suggesting that they could have a common ancestor.

CHOROLOGICAL ANALYSIS AND PHENOLOGICAL OBSERVATIONS OF SOME SPECIES OF THE FAMILY CRASSULACEAE J.ST.-HIL. IN THE LESSER CAUCASUS OF AZERBAIJAN

Research has been carried out in some characteristic areas of Azerbaijan in recent years. The results of the chorological analyses showed that species of the Crassulacea in Irano-Turanian province, are distributed in two or three territories of this province. The results of phenological observations and morphometric parameters indicate that all species have successfully passed through all stages of development. The sequence of seasonal changes in the same community is repeated from year to year, but the timing of the phases and individual details are different. As a result of the study of phenological features, the plants with the earliest start of vegetation, as well as early flowering and fruiting were identified. P. stolonifer, and S. acre are the plants with the earliest beginning of vegetation, as well as early flowering and fruiting. Fruits of plants of the Crassulaceae genus ripen in July. 1 species of hare cabbage (Sedum acre) is found only in the Lesser Caucasus, two species (S. hispanicum, S. pentapetalum Boriss.) are found throughout Azerbaijan, 6 species (Prometheum pilosum, Phedimus spurius, Sedum gracile, S. pallidum, S.annum, Petrosedum subulatum) in the territory of the Greater and Lesser Caucasus, Nakhichevan (Diabar), Lankaran, one species (Phedimus stoloniferum) of the Greater Caucasus, the Lesser Caucasus, Lankaran, one species (Sedum tenellum) in the territory of the Greater Caucasus, the Lesser Caucasus, Lankaran, one species (Sedum album) in the Lesser Caucasus, in Nakhichevan, 1 species (Prometheum sempervivoides) distributed in the regions of Nakhichevan, Lesser Caucasus, Lankaran.

Transcriptome and weighted gene co-expression network analyses reveal key genes and pathways involved in early fruit ripening in Citrus sinensis

BackgroundThe fruit ripening period is an important target trait in fruit tree crop breeding programs. Thus, citrus tree breeders seek to develop extreme early ripening cultivars that allow optimization of citrus maturation periods. In this study, we explored the regulatory network involved in fruit ripening in Citrus sinensis using the ‘Newhall’ navel orange variety and its early-ripening mutant, ‘Gannanzao’. This research will provide a basis for further research on important signaling pathways, gene functions and variety breeding of Citrus sinensis related to fruit ripening period.ResultsPhysiological analyses suggested that early fruit ripening in ‘Gannanzao’ is regulated by early accumulation of abscisic acid (ABA), persistently high levels of jasmonic acid (JA), and higher sucrose content in the pericarp. Pericarp samples from ‘Gannanzao’ and ‘Newhall’ navel oranges were sampled for RNA sequencing analysis at 180, 200, and 220 days after flowering; 1430 differentially expressed genes (DEGs) were identified. Functional enrichment analysis indicated that these DEGs were mainly enriched in the plant hormone signal transduction and sugar metabolism pathways, as well as other pathways related to fruit ripening. Important DEGs associated with fruit ripening in ‘Gannanzao’ included genes involved in ABA and JA metabolism and signal transduction, as well as sugar metabolism. Weighted gene co-expression network analysis showed that the deep pink module had the strongest correlations with ABA content, JA content, and early ripening. Based on gene functionality and gene expression analyses of 37 genes in this module, two candidate hub genes and two ethylene response factor 13 (ERF13) genes (Cs_ont_5g000690 and Cs_ont_5g000700) were identified as key genes regulated by ABA and JA signaling. These findings will help to clarify the mechanisms that underlie early citrus fruit ripening and will lead to the development of excellent genetic resources for further breeding of extreme early-ripening varieties.ConclusionsThrough analyses of the ‘Newhall’ navel orange cultivar and its early-ripening mutant ‘Gannanzao’, we identified genes involved in ABA and JA metabolism, signal transduction, and sugar metabolism that were related to fruit ripening. Among these, two ERF13 genes were inferred to be key genes in the regulation of fruit ripening. These findings provide insights into the genetic architecture related to early fruit ripening in C. sinensis.

ALA Promotes Sucrose Accumulation in Early Peach Fruit by Regulating SPS Activity.

5-Aminolevulinic acid (ALA), as a novel plant growth regulator, is a critical precursor for the biosynthesis of porphyrin compounds in all organisms. Many studies have reported that exogenous ALA treatment could improve fruit sweetness. However, the mechanism by which ALA promotes the increase in sugar content in fruit remains unclear. In this study, we found that ALA significantly promoted sucrose accumulation and SPS (sucrose phosphate synthase) activity in peach fruit. At 14, 28, 42, 50 and 60 days after ALA treatment, sucrose content of fruit was increased by 23%, 43%, 37%, 40% and 16%, respectively, compared with control treatment, and SPS enzyme activity was increased by 21%, 28%, 47%, 37% and 29%, respectively. Correlation analysis showed that the sucrose content of peach fruit under ALA treatment was significantly positively correlated with SPS activity. Subsequently, bioinformatics was used to identify SPS gene family members in peach fruit, and it was found that there were four members of the PpSPS gene family, distributed on chromosomes 1, 7 and 8, named PpSPS1, PpSPS2, PpSPS3 and PpSPS4, respectively. The results of qRT-PCR showed that PpSPS2 and PpSPS3 were highly expressed in response to ALA during fruit development, and the expression of PpSPS2 was positively correlated with SPS activity and sucrose accumulation in peach fruit. The results of tobacco subcellular localization showed that PpSPS2 was mainly distributed in the cytoplasm and nucleus, while PpSPS3 was mainly distributed in the nucleus. The results of this study will lay the foundation for further study on the functions of PpSPS and the regulation of sugar metabolism during the development and ripening of peach fruit by ALA.

Fruit ripening and postharvest changes in very early-harvested tomatoes.

It is well known that if a fruit is harvested extremely early its development and function are interrupted, and it may never attain full maturity and optimal quality. Reports revealing insights regarding the alterations of maturation, ripening and postharvest quality in very early picked fruits are rare. We examined the effects of early harvesting on tomatoes by characterizing different accessions at the molecular, physiological, and biochemical levels. We found that even very early-harvested fruits could achieve postharvest maturation and ripening though with some defects in pigment and cuticle formation, and seeds from very early-harvested fruits could still germinate and develop as normal and healthy plants. One critical regulator of tomato cuticle integrity, SlCER1-2, was shown to contribute to cuticle defects in very early-harvested fruits. Very early fruit harvest still allowing ripening and seed development indicate that the genetic and physiological programs of later maturation and ripening are set into motion early in fruit development and are not dependent on complete fruit expansion nor attachment to the plant.

Body plan evolvability: The role of variability in gene regulatory networks.

Recent computational modeling of early fruit fly (Drosophila) development has characterized the degree to which gene regulation networks can be robust to natural variability. In the first few hours of development, broad spatial gradients of maternally derived transcription factors activate embryonic gap genes. These gap patterns determine the subsequent segmented insect body plan through pair-rule gene expression. Gap genes are expressed with greater spatial precision than the maternal patterns. Computational modeling of the gap-gap regulatory interactions provides a mechanistic understanding for this robustness to maternal variability in wild-type (WT) patterning. A long-standing question in evolutionary biology has been how a system which is robust, such as the developmental program creating any particular species' body plan, is also evolvable, i.e. how can a system evolve or speciate, if the WT form is strongly buffered and protected? In the present work, we use the WT model to explore the breakdown of such Waddington-type 'canalization'. What levels of variability will push the system out of the WT form; are there particular pathways in the gene regulatory mechanism which are more susceptible to losing the WT form; and when robustness is lost, what types of forms are most likely to occur (i.e. what forms lie near the WT)? Manipulating maternal effects in several different pathways, we find a common gap 'peak-to-step' pattern transition in the loss of WT.We discuss these results in terms of the evolvability of insect segmentation, and in terms of experimental perturbations and mutations which could test the model predictions. We conclude by discussing the prospects for using continuum models of pattern dynamics to investigate a wider range of evo-devo problems.

The RNA-seq and BSA-seq analysis reveals genes associated to the control of early fruiting in walnut (Juglans regia L.)

Walnut is an important nut worldwide. The duration of the juvenile phase has a considerable impact on walnut yield. Floral transition is critical for walnut flowering and fruit setting. To improve walnut breeding, it is critical to study the mechanisms of early blooming and fruiting in early-fruiting (EF) walnuts and shorten their juvenile stages. This work used EF and later-fruiting (LF) walnuts to screen for genes associated with walnut early fruiting using RNA sequencing (RNA-seq) and bulk segregant analysis sequencing (BSA-seq). Thirty-seven key differential genes were analyzed using weighted gene co-expression network association (WGCNA) in RNA-seq, and FT, CAL, FUL, and APRR9 genes were found to be able to shorten the juvenile phase of plants by affecting the floral transition process and influencing plant fruiting time. BSA-seq was utilized to identify 3305656 SNPs and 596640 InDels in EF walnut and 925347 SNPs and 514751 InDels in LF walnut. A combined analysis of RNA-seq and BSA-seq revealed 49 structurally varied DEGs in both kinds, with 47 genes in the NC_049914.1 region, one gene in NC_049901.1, one gene locus in NC_049908.1, and eight structurally variant DEGs found solely in early fruiting walnuts. The analysis of candidate genes and verification of RT-qPCR expression revealed that JrLOC109015871 (JrPBL12), JrLOC108983551 (WRI1-like), JrLOC109016788 (WRKY12), and AP2-like genes are likely to be related to early fruiting of walnut, with WRKY12 being expressed at the highest level during the flowering peak of early fruiting walnut. It is likely that the WRKY12 gene regulates the flowering transition of walnut through the ageing pathway, allowing walnut to complete the transition from nutrient growth to reproductive growth more quickly and realize early fruiting to increase walnut yield, laying the groundwork for the study of the molecular mechanism of walnut's early fruiting trait.