Rice and BBX proteins: toward genetic engineering of abiotic stress resistant crops.

Productivity of crop plants are enormously affected by biotic and abiotic stresses. The co-occurrence of several abiotic stresses may lead to death of crop plants. Hence, it is the responsibility of plant scientists to develop crop plants equipped with multistress tolerance pathways. A subgroup of zinc finger transcription factor family, known as B-box (BBX) proteins, play a key role in light and hormonal regulation pathways. In addition, BBX proteins act as key regulatory proteins in many abiotic stress regulatory pathways, including Ultraviolet-B (UV-B), salinity, drought, heat and cold, and heavy metal stresses. Most of the BBX proteins identified in and rice respond to more than one abiotic stress. Considering the requirement of improving rice for multistress tolerance, this review discusses functionally characterized and rice BBX proteins in the development of abiotic stress responses. Furthermore, it highlights the participation of BBX proteins in multistress regulation and crop improvement through genetic engineering.