Physiological and transcriptional responses of Alternaria alternata induced abnormal leaf senescence in Pyrus pyrifolia

•Alternaria alternata infection is one of major factors for abnormal leaf senescence of Pyrus pyrifolia.•ABA signaling participated in Alternaria alternata induced abnormal leaf senescence.•Abnormal leaf senescence restricted redistribution of foliar N, P and K.•The expression pattern analysis of SAGs implied abnormal pear leaf senescence via an unconventional pathway.