Comprehensive transcriptome analysis provides novel insight into pistil abortion mechanism in Japanese apricot

Flower development is a key stage in the life cycle of fruit trees and its proper development is considered its reproductive success. Pistil abortion is a widely distributed phenomenon in fruit plants and its mechanism in Japanese apricot is quite unclear. The present study was carried out to get a deep insight about the regulatory mechanism of pistil abortion in Japanese apricot using transcriptomic approach. A large number of DEGs (24,683) were identified in normal (N) and abortive pistil stages i.e. style browning (STYB), stigma browning (STIB) and ovary browning (OVB). Pair-wise comparison analysis was performed as N vs STYB, N vs STIB, N vs OVB and STIB vs OVB, and produced 9592, 8691, 8660 and 8103 transcripts, respectively. The Gene Ontology (GO) showed that different metabolic processes, plant hormones, flower development and photosystem related genes were involved in pistil abortion. The pathway analysis revealed that plant hormones signal transduction and circadian rhythm pathways were found significantly enriched. Furthermore, transcription factors such as MYB, MADS-box and NAC family remained highly expressed. Maximum number of the genes were grouped to cluster 11, and were highly expressed at OVB stage, suggesting that this stage might be critical for pistil abortion. This study provides an alternatives to be consider for further studies and understanding of pistil abortion processes in Japanese apricot, and provide a reference related to this issue for other deciduous fruit crops. Overall design: The flower buds of Japanese apricot (P. mume) cv. 'Daqiandi' and 'Longyan' were collected Longyan pistils were used as normal pistil (control) and Daqiandi pistils were used as abortive pistils. Three key stages of pistil abortion (cv. Daqiandi pistils) i.e. style browning (STYB), stigma browning (STIB) and ovary browning (OVB) were selected