Copy number variation of a gene cluster encoding endopolygalacturonase mediates flesh texture and stone adhesion in peach

Abstract

HighlightCopy number variation at the F-M locus plays a driving role in flesh texture diversification in peach.

Comparative population genomics identified genomic regions and candidate genes associated with fruit domestication traits in peach

“…We detected three clear signals associated with flesh adhesion and one clear signal associated with texture (Figure S11 and Table S11). The peak signals for the above traits were only 8 and 800 kb away, respectively, from the two polygalacturonase genes previously reported to regulate flesh adhesion and texture (Gu et al ., ).…”

Identification and Expression Analysis of Polygalacturonase Family Members during Peach Fruit Softening

“…Pan et al (2015) indicated that PpPG21 ( ppa006839 ) and - 22 ( ppa006857 ) were relatively highly expressed in ripening peach fruit, but that their transcripts were almost undetectable in fruit during development [52]. Gu et al (2016) also demonstrated that PpPG22 and -21 are responsible for stone adhesion and melting flesh, respectively [25]. The mRNA levels of PpPG1 ( ppa018113 ) were lower in both the melting type and the stony hard type peach, although they increased slightly after ethylene treatment in the stony hard type peach [36].…”

“…However, Smith et al thought PG was not essential for tomato fruit softening [21]. Interestingly, peach fruit melting and freestone are also controlled by Endo-PGs [22,23,24,25]. In addition, PG genes also participate in the organ abscission of lychee, oilseed rape, Arabidopsis and tomato [26,27,28].…”

“…These studies have demonstrated that PG members are differentially expressed in specific tissues and in response to specific treatments, indicating extensive functional divergence among plant PG genes. Although the important roles of PG hydrolase in peach softening were confirmed by many researches [3,4,34], only a small number of PG family members have been reported [25,34,35,36]. To clarify which PG members are involved in softening of peach fruit, in this study, we identify 45 members of the PG family from the whole genomic sequence of peach and analyze the expression profiles of PpPG genes during fruit softening in two peach cultivars that have different softening characteristics.…”

<i>Endopolygalacturonase</i> Gene Polymorphisms: Asset of the Locus in Different Peach Accessions

“…A high degree of allelic diversity has been identified in the peach Pp-endoPG sequence [13] [22] [23]. We previously identified specific SNPs in the open-reading frame of Pp-endoPG, one of which allowed to determine the configuration at the Melting flesh locus in the NM (Oro A) and M (Bolero) model cultivars, and in a few M and NM F 1 seedlings from their cross [5] [23].…”