TabZIP74 Acts as a Positive Regulator in Wheat Stripe Rust Resistance and Involves Root Development by mRNA Splicing

Area of Science:

• Plant molecular biology
• Genetics
• Biochemistry

Background:

• Basic leucine zipper (bZIP) membrane-bound transcription factors (MTFs) regulate plant growth, development, and stress responses.
• bZIP MTFs are crucial in endoplasmic reticulum (ER) stress signaling pathways.

Purpose of the Study:

• To isolate and characterize a novel wheat bZIP MTF, TabZIP74.
• To investigate the role of TabZIP74 in wheat's response to biotic and abiotic stresses.

Main Methods:

• Isolation of TabZIP74 cDNA from wheat near-isogenic lines.
• Phylogenetic analysis comparing TabZIP74 to homologous proteins in maize and rice.
• Analysis of TabZIP74 mRNA splicing under stress conditions (Pst infection, PEG, ABA).
• Confocal microscopy to observe TabZIP74 localization.
• Gene silencing using Barley Stripe Mosaic Virus-induced Gene Silencing (BSMV-VIGS) to assess TabZIP74 function.

Main Results:

• TabZIP74 mRNA undergoes splicing under biotic (Puccinia striiformis f. sp. tritici - Pst) and abiotic (PEG, ABA) stress, producing a protein lacking a transmembrane domain.
• TabZIP74 protein translocates to the nucleus upon wounding.
• Gene silencing of TabZIP74 increased susceptibility to stripe rust, reduced drought tolerance, and impaired lateral root development.

Conclusions:

• TabZIP74 plays a critical role in regulating wheat's response to stripe rust and drought stress.
• TabZIP74 is essential for normal lateral root development in wheat.
• Stress-induced alternative splicing of TabZIP74 mRNA is a key regulatory mechanism.