Gasotransmission of Nitric Oxide (NO) at Early Plant Developmental Stages

The versatility of nitric oxide (NO) as a free radical that mediates numerous biological functions within early plant development is widely accepted. NO action in seed germination and root developmental processes involves a complex signaling pathway that includes the cellular redox levels, the posttranslational modification of specific proteins by S-nitrosylation, and the interaction with other plant growth regulators (i.e., phytohormones) using similar molecular components. Recent evidence indicates that changing levels of this reactive nitrogen species (NO) may also fine-tune the molecular mechanisms by which NO leads to changes in seed germination and root growth. This chapter briefly introduces the key processes for the NO transmission during seed germination and root development and focuses on the sensing mechanisms underlying the effects of NO and its interaction with other plant hormones linking these changes.