BIIDXI, a DUF642 Cell Wall Protein That Regulates Pectin Methyl Esterase Activity, Is Involved in Thermotolerance Processes in Arabidopsis thaliana

The Mechanism of Ovule Abortion in Self-Pollinated 'Hanfu' Apple Fruits and Related Gene Screening

Apples exhibit S-RNase-mediated self-incompatibility and typically require cross-pollination in nature. 'Hanfu' is a cultivar that produces abundant fruit after self-pollination, although it also shows a high rate of seed abortion afterwards, which greatly reduces fruit quality. In this study, we investigated the ovule development process and the mechanism of ovule abortion in apples after self-pollination. Using a DIC microscope and biomicroscope, we found that the abortion of apple ovules occurs before embryo formation and results from the failure of sperm-egg fusion. Further, we used laser-assisted microdissection (LAM) cutting and sperm and egg cell sequencing at different periods after pollination to obtain the genes related to ovule abortion. The top 40 differentially expressed genes (DEGs) were further verified, and the results were consistent with switching the mechanism at the 5' end of the RNA transcript (SMART-seq). Through this study, we can preliminarily clarify the mechanism of ovule abortion in self-pollinated apple fruits and provide a gene reserve for further study and improvement of 'Hanfu' apple fruit quality.

Tissue-specific proteome profile analysis reveals regulatory and stress responsive networks in passion fruit during storage

Passiflora edulis, commonly known as passion fruit, is a crop with a fragrant aroma and refreshingly tropical flavor that is a valuable source of antioxidants. It offers a unique opportunity for growers because of its adaptability to tropical and subtropical climates. Passion fruit can be sold in the fresh market or used in value-added products, but its postharvest shelf life has not been well-researched, nor have superior cultivars been well-developed. Understanding the proteins expressed at the tissue level during the postharvest stage can help improve fruit quality and extend shelf life. In this study, we carried out comparative proteomics analysis on four passion fruit tissues, the epicarp, mesocarp, endocarp, and pulp, using multiplexed isobaric tandem mass tag (TMT) labeling quantitation. A total of 3352 proteins were identified, including 295 differentially expressed proteins (DEPs). Of these DEPs, 213 showed a fold increase greater than 1.45 (50 proteins) or a fold decrease less than 0.45 (163 proteins) with different patterns among tissue types. Among the DEPs, there were proteins expressed with functions in oxygen scavenging, lipid peroxidation, response to heat stress, and pathogen resistance. Thirty-six proteins were designated as hypothetical proteins were characterized for potential functions in immunity, cell structure, homeostasis, stress response, protein metabolism and miraculin biosynthesis. This research provides insight into tissue-specific pathways that can be further studied within fruit physiology and postharvest shelf life to aid in implementing effective plant breeding programs. Knowing the tissue-specific function of fruit is essential for improving fruit quality, developing new varieties, identifying health benefits, and optimizing processing techniques.