GA 3 mediated mechanism of HLB mitigation in citrus

Abstract

Huanglongbing (HLB), also known as citrus greening, poses a significant threat to the global citrus industry. The disease, spread by the Asian citrus psyllid (ACP), causes severe symptoms in citrus plants, leading to substantial yield losses and tree mortality. Gibberellic acid (GA3) has emerged as a promising tool for mitigating HLB-induced stress in citrus plants. In HLB-infected trees, GA3 plays a crucial role in countering both biotic stresses. GA3 modulates systemic acquired resistance (SAR) by upregulating genes involved in plant immune responses. It also enhances cuticle formation and integrity, promoting better growth and reduced disease severity. By degrading DELLA proteins, GA3 shifts the plant’s balance towards growth over defence, thus improving the overall health and productivity of citrus plants affected by HLB. These findings suggest that GA3 not only aids in stress tolerance but also acts as an immunoregulator, highlighting its potential in sustainable citrus management against HLB.