A unique bZIP transcription factor imparting multiple stress tolerance in Rice

Area of Science:

• Plant Science
• Molecular Biology
• Genetics

Background:

• Environmental stresses significantly reduce rice productivity.
• Transcription factors (TFs) regulate gene expression and are crucial for stress tolerance and crop yield.
• Histone gene binding protein-1b (OsHBP1b) is a TF in rice, located within the Saltol QTL, known to influence stress tolerance.

Purpose of the Study:

• To investigate the role of OsHBP1b in conferring multiple abiotic stress tolerance in rice.
• To assess the impact of over-expressing OsHBP1b on grain yield in rice.

Main Methods:

• Over-expression of the full-length OsHBP1b gene in a homologous rice system.
• Evaluation of transgenic rice plants under salinity, drought, and high-temperature stress conditions.
• Analysis of physiological parameters, antioxidant enzyme activity, and gene expression.

Main Results:

• Transgenic rice over-expressing OsHBP1b showed enhanced survival and osmotic regulation under salinity stress.
• These plants exhibited increased antioxidant enzyme activity (ascorbate peroxidase, superoxide dismutase) and maintained chlorophyll concentration and photosynthetic efficiency.
• Improved tolerance to drought and high temperatures was observed, with better growth, photosynthetic parameters, and antioxidant activity. Root structure modifications facilitated soil penetration and ion exclusion.

Conclusions:

• The rice HBP1b gene confers multiple abiotic stress tolerance via various molecular and physiological mechanisms.
• OsHBP1b is a promising candidate gene for enhancing stress resilience and improving crop yield in rice.