Passion fruit (Passiflora edulis Sims) can be divided into yellow and purple varieties. However, information about coloration and fruit quality between the two varieties is limited. To reveal the underlying mechanism of color formation in this fruit, a combined analysis of the metabolome and transcriptome was conducted in this study. The results showed that most of the evaluated flavonols, anthocyanins, and flavanols were significantly upregulated in purple fruit compared to their levels in yellow fruit. Flavonoid and flavonoid carbonoside accumulation was markedly higher in yellow fruit than in purple fruit. The accumulation of organic acids, phenolic acids, lipids, sugars, and lignans was significantly different in the yellow and purple varieties. These results were consistent with the results from the RNA-Seq profile. This study will enable us to identify genes for targeted genetic engineering to improve the nutritional and market value of passion fruit. In addition, the peel and pulp of passion fruit contained certain health-promoting compounds, highlighting the potential application of passion fruit as a functional food and providing direction for future breeding programs and production.

The maize inbred lines Huangzao 4 (HZ4) and Chang 7-2 (C7-2) are the foundation genotypes key to maize cross-breeding in China. C7-2 is derived from HZ-4. In this study, changes in phenotype, physiology and gene expression of three-leaf-old seedlings of HZ4 and C7-2 under the conditions of progressive water deficit (WD) and re-watering (RW) were compared to gain knowledge for breeding new maize foundation genotypes with higher drought tolerance. Progressive WD was produced by adding polyethylene glycol (PEG 6000) at 24 h intervals (24, 48 and 72 h) in Hoagland's nutrient solution, resulting in water potentials of -0.15, -0.3 and -0.5 MPa. The seedlings treated for 24 h at -0.5 [corrected] MPa were subjected to RW in the solution without complementation with PEG. The results showed that C7-2 seedlings are more tolerant to progressive WD than HZ4 seedlings in part because the former have a larger stomatal resistance, a relatively stronger leaf water-holding capacity, and a timely and stable increase in activities of antioxidant enzymes (superoxide dismutase and peroxidase) especially in roots upon WD. Oligonucleotide probe array-based analysis uncovered a number of WD- and RW-regulated genes in both inbred lines, and clearly indicated that fine transcriptional coordination between maize leaves and roots is one of the factors constituting higher WD tolerance and a greater ability for growth recovery from WD. On the basis of the resulting data and co-regulation of responsive genes in tissues, we propose a model for the whole maize plant tolerance to growth and recovery from WD.

Wampee is one of the characteristic fruits in southern China, and its brittle and thin skin can easily be damaged. In this study, principal components analysis (PCA) and minimum noise fraction (MNF) analysis were carried out on the two wampee varieties by hyperspectral imaging technology, and 680nm was determined to be the optimal characteristic wavelength. The accurate recognition rate obtained from PCA algorithm for wampee samples of two varieties was about 83.75%, and that obtained from MNF algorithm for two variety samples was 85%. It was indicated that the wampee damaged can be identified more accurately and effectively by MNF based on hyperspectral imaging technology

Changes of and correlation among root tolerance index (RTI), root Aluminum (Al) content, root/shoot ratio (RSR), root malondialdehyde (MDA) content, and Superoxide dismutase (SOD) and peroxidase (POD) isoforms of maize YQ 7-96 were investigated under Al stress and removal of the stress (RS). Consequently, Al stress led to significant decreases in RTI, RSR, SOD and POD activities, but resulted in significant increase in root MD A and, Al accumulation in the tissues; Root SOD and POD activities did not correlate with Al and MDA contents in roots; The activities of SOD and POD were much lower in roots than in leaves. It can be concluded that (1) Al stress can lead to lipid peroxidation; (2) there is a larger POD family composed of different POD isoforms, some of which are of tissue-specific expression and play different roles in detoxification of Al in maize; (3) for POD isoforms, POD 2 is root-specific. POD 6 and POD 7 are all leaf-specific, POD 5 is not only root-specific but also RS-responsive; (4) high sensitivity of maize to Al is in part associated with much lower activities of both SOD and POD in roots; and (5) more importantly, both SOD and POD are therefore hinted to be not key players in prevention against Al-induced lipid peroxidation

Complex metabolic components in mango leaves lead to high difficulty in RNA extraction. In order to improve the quality of total RNA extraction, on the basis of the existing methods reported in the literature, an RNA extraction method combining acetone washing liquid nitrogen abrasive material with 0.3 mol/L lithium chloride (LiCl) solution and 2 times the volume of anhydrous ethanol as the second precipitator was developed. The experimental results showed that the improved method significantly reduced the amount of impurity precipitation in the RNA extraction process. The electrophoretic bands of total RNA extracted were complete. The absorbance ratio of OD260/280 was about 1.9, and the average was 329.8 g/g FW±11.2 g/g FW. Further validation experiments of RNA reverse transcription and the polymorphic amplification of double-stranded cDNA related sequences (RAP-PCR) obtained clear polymorphic bands, showing that the total RNA from mango leaves had high quality and was suitable for molecular biology experiments.