Recently, two heat shock factors (EjHSF1 and EjHSF3) were reported as the novel regulator on loquat fruit lignification, which was online published at Plant Cell and Environment. Dr. Jiaoke Zeng, Dr. Xian Li and Dr. Xueren Yin are first-, co-first- and corresponding-authors for this paper.
Loquat (Eriobotrya japonica Lindl.) fruit are susceptible to chilling injury, exhibiting a unique phenomenon in the acceleration of lignin accumulation and increasing fruit firmness. Our previous studies characterized a few transcription factors that involved in loquat fruit lignification, with EjMYB1 and EjMYB2 were firstly isolated and directly regulated lignin-related genes (Journal of Experimental Botany, 2014, 65: 4349-4359; Corresponding author is Dr. Kunsong Chen). Subsequently, an AP2/ERF transcription factor, EjAP2-1 was characterized a putative repressor on lignification, via interact with EjMYB1/2 at protein level (Plant Biotechnology Journal, 2015, 13: 1325-1334; Corresponding author is Dr. Xue-ren Yin). Heat treatment (HT) is effective to alleviate loquat lignification, which led us to conduct the HSF researches. The present research showed that HSF are involved in loquat fruit chilling injury and induced lignification via two distinct pathways. EjHSF1 transcriptionally regulated EjHsp genes (a conventional regulatory pathway), while EjHSF3 interacted with EjAP2-1 and regulated lignin biosynthetic genes. These researches were supported by NSFC and 973.
