J Integr Plant Biol. ›› 2019, Vol. 61 ›› Issue (5): 598-610.DOI: 10.1111/jipb.12766
• Research Articles •
Wei Wang, Hanxian Xiong, Rongxin Lin, Nantian Zhao, Peng Zhao* and Meng-Xiang
Programmed cell death (PCD) is an essential process for development, and shows conserved cytological features in both plants and animals. Caspases are well-known critical components of the PCD machinery in animals. However, currently few typical counterparts have been identified in plants and only several caspase-like proteases are known to be involved in plant PCD, indicating the existence of great challenge for confirming new caspase-like proteases and elucidating the mechanisms regulating plant PCD. Here, we report a novel cysteine protease, NtTPE8, which was extracted from tobacco seeds and confirmed as a new caspase-like protease. Recombinant NtTPE8 exhibited legumain and caspase-like proteolytic activities, both of which could be inhibited by the pan-caspase inhibitor (Z-VAD-FMK). Notably, NtTPE8 possessed several caspase activities and the capacity to cleave the cathepsin H substrate FVR, indicating a unique character of NtTPE8. NtTPE8 was exclusively expressed in the integumentary tapetum and thus, is the first specific molecular marker reported to date for this cell type. Down-regulation of NtTPE8 caused seed abortion, via disturbing early embryogenesis, indicating its critical role in embryogenesis and seed development. In conclusion, we identified a novel caspase-like cysteine protease, NtTPE8, exclusively expressed in the integumentary tapetum that is involved in seed development.
Wei Wang, Hanxian Xiong, Rongxin Lin, Nantian Zhao, Peng Zhao and Meng-Xiang Sun. A VPE-like protease NtTPE8 exclusively expresses in the integumentary tapetum and is involved in seed development[J]. J Integr Plant Biol., 2019, 61(5): 598-610.
Add to citation manager EndNote|Ris|BibTeX