AUTHOR=Zhang He , Gao Siyang , Wang Tianye , Xu Mingyang , Li Xinyue , Du Guodong 

TITLE=Ca2+ mediates transcription factor PuDof2.5 and suppresses stone cell production in pear fruits

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.976977

DOI=10.3389/fpls.2022.976977

ISSN=1664-462X

ABSTRACT=<p>Stone cells are sclerenchyma cells formed by deposition of lignin, which is the most significant factor limiting the quality of pears. Ca<sup>2+</sup> was known to inhibit stone cells in pear fruits, but the underlying molecular mechanism remains unclear. Our study revealed that exogenous CaCl<sub>2</sub> (Ca<sup>2+</sup>) treatment of “Nanguo” pear (<italic>Pyrus ussuriensis</italic>) suppressed the synthesis of lignin and stone cell production. We further analysed the transcriptomes using RNA-seq, identified a transcription factor, <italic>PuDof2.5</italic>, and its targets gene <italic>PuPRX42-like</italic> (lignin polymerase gene) expression decreased in CaCl<sub>2</sub>-treated samples, which are involved in suppressing lignin biosynthesis in pear fruit. <italic>PuDof2.5</italic> was found to bind directly to the <italic>PuPRX42-like</italic> promoter and induced its transcription. Taken together, our results revealed that Ca<sup>2+</sup> modulated the key lignin biosynthetic transcription factor <italic>PuDof2.5</italic> to suppress stone cell production in pear fruits.</p>