The Arabidopsis CALCINEURIN B-LIKE10 protein mediates flower development during plant growth in saline conditions

Annie Yen , Dr. Shea Monihan, Dr. Karen Schumaker

The Arabidopsis CALCINEURIN B-LIKE10 protein mediates flower development during plant growth in saline conditions

In the next forty years, the world population is expected to grow to over 9 billion people, while the amount of agricultural land available will remain about the same. One major challenge for agriculture is the accumulation of salt in soils which decreases the growth and yield of crop plants. Sodium, a major component of salt, reduces plant growth by interfering with metabolic processes in the cell. Three proteins have been shown to remove sodium from the cell and prevent its toxic accumulation in the model plant Arabidopsis thaliana. The perception of sodium results in an increase in cytosolic calcium which is perceived by the CALCINEURIN B-LIKE (CBL10) calcium-binding protein. Upon binding calcium, CBL10 interacts with and activates the SALT-OVERLY-SENSITIVE2 (SOS2) protein kinase. The CBL10-SOS2 complex then activates the SOS1 sodium proton exchanger which transports sodium out of the cell. While the genes that function to remove sodium from cells in leaves and roots have been identified, little is known about the genes that function to protect flower development. To determine if the CBL10-SOS2-SOS1 pathway functions in flowers, we analyzed flower development in mutants of this pathway. We found that CBL10 is required for flower development and fertilization during salt stress, but that it functions independently of SOS2 and SOS1. This suggests that CBL10 most likely functions with another kinase and another exchanger in flowers. SOS2 belongs to a family of 25 protein kinases and SOS1 to a family of 8 sodium proton exchangers. To identify family members that function with CBL10, we are determining which genes are expressed in flowers and if their expression changes in response to salt.

Conference Home | List of Abstracts | Photo Gallery