In response to several biotic and abiotic stresses, In ToMV interaction Pentatricopeptide-repeat, ATP-dependent and RNA helicase could be involved in the process of silencing and virus replication. A high level of NB-ARC genes activation and of other gene classes potentially involved in pathogen recognition was also found, suggesting a host-coordinated reaction of defense machinery to monitor integrity of cellular proteins. The NB-ARC system minimizes the cost of defense for the plant, as multiple NB-ARCLRR proteins can be maintained at a low level in the absence of a pathogen and rapidly induced under pathogen attack through miRNA regulation. Pathogen-encoded suppressors of RNAsilencing mechanisms might result in the induction of multiple NBARC-LRR defense proteins. Investigation of differentially regulated pathogen recognition genes could lead to the identification of specific modulation patterns. Albeit still fragmented, our depiction provides a global view of the I-I2 and Tm2 mediated resistance process, in which the gene expression network may be considered the starting point to construct a genomic model for R-mediated response in the two pathosystems investigated. Some of these units could also be esterified with other moleculars such as glucose or gallic acid. The chromatographic separation of PAs is complicated because of the enormous variety of similar isomeric oligomers in plant or food sources. PAs are used for treating periodontal diseases. They have also been reported to demonstrate antioxidant, antimicrobial, anti-diabetic, anti-angiogenic, anticarcinogenic, anti-inflammatory and antimelanogenic activities. Chinese bayberry is a subtropical evergreen fruit tree widely grown in Southern China. Most of its cultivars in China blossom in March and April, and then the fruit ripens in June and July. In the book of Chinese herbal medicine, Compendium of Materia Medica, medical application of the leaf cures enteritis and arthralgia and promotes hemostasis. Recent research has mainly focused on the function of myricetin isolated from M. rubra Sieb. et Zucc. leaves, including analgesic and anti-inflammatory activities. Research on PAs of M. rubra Sieb. et Zucc. leaves are limited. Masuda et al. identified two monomers ; Yang et al. identified five flavan-3-ol monomers and oligomeric PAs, and elucidated the structural features of bayberry leaf PAs by using acidic degradation. The main objective of this work was to characterize the structures of PAs extracted from Chinese bayberry leaves. This was achieved by fractionation on normal-phase HPLC at preparative scale to enable separation of PAs according to their polymerization degrees. Further fractionation facilitated their analysis by reversed-phase HPLC coupled to UV–visible spectroscopy and electrospray ionization mass spectrometry. The combination of NP and RP-HPLC to identify proanthocyanidins has rarely been used.