Genome-wide characterization of NtHD-ZIP IV: different roles in abiotic stress response and glandular Trichome induction.
BACKGROUND
The plant-specific homeodomain-leucine zipper class IV (HD-ZIP IV) gene family has been involved in the regulation of epidermal development.


RESULTS
Fifteen genes coding for HD-ZIP IV proteins were identified (NtHD-ZIP-IV-1 to NtHD-ZIP-IV-15) based on the genome of N. tabacum. Four major domains (HD, ZIP, SAD and START) were present in these proteins. Tissue expression pattern analysis indicated that NtHD-ZIP-IV-1, - 2, - 3, - 10, and - 12 may be associated with trichome development; NtHD-ZIP-IV-8 was expressed only in cotyledons; NtHD-ZIP-IV-9 only in the leaf and stem epidermis; NtHD-ZIP-IV-11 only in leaves; and NtHD-ZIP-IV-15 only in the root and stem epidermis. We found that jasmonates may induce the generation of glandular trichomes, and that NtHD-ZIP-IV-1, - 2, - 5, and - 7 were response to MeJA treatment. Dynamic expression under abiotic stress and after application of phytohormones indicated that most NtHD-ZIP IV genes were induced by heat, cold, salt and drought. Furthermore, most of these genes were induced by gibberellic acid, 6-benzylaminopurine, and salicylic acid, but were inhibited by abscisic acid. NtHD-ZIP IV genes were sensitive to heat, but insensitive to osmotic stress.


CONCLUSION
NtHD-ZIP IV genes are implicated in a complex regulatory gene network controlling epidermal development and abiotic stress responses. The present study provides evidence to elucidate the gene functions of NtHD-ZIP IVs during epidermal development and stress response.
['Zhang|Hongying|H|', 'Ma|Xudong|X|', 'Li|Wenjiao|W|', 'Niu|Dexin|D|', 'Wang|Zhaojun|Z|', 'Yan|Xiaoxiao|X|', 'Yang|Xinling|X|', 'Yang|Yongfeng|Y|', 'Cui|Hong|H|']
D018506:Gene Expression Regulation, Plant D053263:Gene Regulatory Networks D016350:Leucine Zippers D010940:Plant Proteins D013312:Stress, Physiological D014026:Tobacco D064201:Trichomes
Expression pattern MeJA ABA GA Nicotiana tabacum SA