MdNup62 interactions with MdHSFs involved in flowering and heat-stress
tolerance in apple
Abstract
Because of global warming, the apple flowering period is occurring
significantly earlier, increasing the probability and degree of freezing
injury. Moreover, extreme hot weather has also seriously affected the
development of apple industry. Nuclear pore complexes (NPCs) are main
channels controlling nucleocytoplasmic transport, but their roles in
regulating plant development and stress responses are still unknown.
Here, we analysed the components of the apple NPC and found that MdNup62
interacts with MdNup54, forming the central NPC channel. MdNup62 was
localized to the nuclear pore, and its expression was significantly
up-regulated in ‘Nagafu No. 2’ tissue-cultured seedlings subjected to
heat treatments. To determine MdNup62’s function, we obtained
MdNup62-overexpressed (OE) Arabidopsis and tomato lines that showed
significantly reduced high-temperature resistance. Additionally,
OE-MdNup62 Arabidopsis lines showed significantly earlier flowering
compared with wild-type. Furthermore, we identified 62 putative
MdNup62-interacting proteins and confirmed MdNup62 interactions with
multiple MdHSFs. The OE-MdHSFA1d and OE-MdHSFA9b Arabidopsis lines also
showed significantly earlier flowering phenotypes than wild-type, but
had enhanced high-temperature resistance levels. Thus, MdNUP62 interacts
with multiple MdHSFs during nucleocytoplasmic transport to regulate
flowering and heat resistance in apple. The data provide a new
theoretical reference for managing the impact of global warming on the
apple industry.