Comparative Analyses of Dormancy-associated MADS-box Genes, PpDAM5 and PpDAM6, in Low- and High-chill Peaches (Prunus persica L.)

Abstract

This study investigated the regulation of the seasonal expression of PpDAM5 and PpDAM6, two of the six peach (Prunus persica) dormancy-associated MADS-box genes, in relation to the endodormancy and development of lateral vegetative and flower buds of low-and high-chill peach cultivars. PpDAM5 and PpDAM6 were originally found as homologs of Arabidopsis SVP/AGL24 at the EVERGROWING (EVG) locus of peach and have been recently shown to be involved in lateral bud endodormancy. Seasonal expression analyses in this study indicated that PpDAM5 and PpDAM6 transcript levels in lateral vegetative buds of both low-and high-chill cultivars in the field negatively correlated with bud burst percentages determined under forcing conditions. Negative correlation was also found between their transcript levels and the flower organ enlargement rate. These results suggest that distinct seasonal expression patterns of PpDAM5 and PpDAM6 are correlated with a distinct chilling requirement for bud break and flowering of low-and high-chill cultivars. Characterization of the genomic structure of PpDAM5 and PpDAM6 revealed the presence of large insertions in the first introns of both PpDAM5 and PpDAM6 in low-chill peach. Alteration of the genomic structure is discussed with respect to the low-chill character.

Chilling Requirements and Blooming Dates of Leading Peach Cultivars and a Promising Early Maturing Peach Selection, Momo Tsukuba 127

“…In our experiment, the CU for 'Chimarrita' were about 430, which is consistent with the 350 CU already reported by Topp et al (2008). Similarly, the CU that we found for 'Akatsuki' and 'Shimizuhakutou' (1065 and 1130, respectively) were consistent with those reported by Yamane et al (2011), which were both about 1000 CU. These results indicate that our data are reliable.…”

“…In this paper, we analyzed the relationships between chilling requirements, heat requirements, and blooming dates of the leading peach cultivars in Japan, along with those of Momo Tsukuba 127, for 11 years at NIFTS in Tsukuba and at 24 other locations within the temperate zone of Japan. Because many quantity studies (Topp et al, 2008), genetic or phonologic studies (Yamane et al, 2011;Yooyongwech et al, 2006), and QTL analyses (Fan et al, 2010) of peach chilling requirements have employed the Utah model to determine CU (Richardson et al, 1974), we used this model to determine the chilling requirements in this study.…”

“…The dates of rest completion (endodormancy breaking), were determined as described previously (Shenghua et al, 2010;Weinberger, 1950;Werner et al, 1988;Yamane et al, 2011). Three annual shoots (approximately 30-50 cm and populated with floral buds) were taken from each tree ( Table 1).…”

Insertion of a transposon‐like sequence in the 5′‐flanking region of the YUCCA gene causes the stony hard phenotype

“…The CACTA transposons have flanking terminal inverted repeats, which are normally 10–28 bp long and terminate in a conserved 5′‐CACTA‐3′ motif (Wicker et al ., ) (Figures a and S5). Almost the same sequence as the transposon inserted in PpYUC11 was found in the first intron of PpDAM6 (Figure S9), which is a MADS‐BOX gene associated with lateral bud endodormancy (Yamane et al ., ; Zhebentyayeva et al ., ). In PpDAM6 , a 2604‐bp DNA fragment was found only in low‐chill peach cultivars, not in high‐chill ones.…”

Dormancy Behaviors and Underlying Regulatory Mechanisms: From Perspective of Pathways to Epigenetic Regulation

“…Collectively, these results confirm DAM5 and DAM6 as key dormancy regulators. However, the fact that peach cultivars carrying the mutation of both DAM5 and DAM6 still proceed into normal dormancy entry and exit, albeit they require only a short period of for dormancy release (Yamane et al 2011c;Zhebentyayeva et al 2014), strongly suggests that DAMs other than DAM5 and DAM6 are also involved in dormancy regulation.…”