Salicylic acid (SA) regulates hypersensitive response and effector-triggered immunity at the primary infection site and systemic acquired resistance (SAR) in the distal tissues of the plants. Which one of the following statements regarding the functionality of the Non-expressor of PR genes 1 (NPR1) in the distal tissue is correct?
1
NPR1 exists as oligomers in the nucleus and activates hypersensitive response.
2
NPR1 degrades through its binding to NPR3 and leads to activation of SAR response.
3
NPR1 accumulates in the nucleus and leads to activation of SAR response.
4
Binding with NPR4 stabilizes NPR1 in the nucleus, which in turn activates the hypersensitive response.