NO and ABA Interaction Regulates Tuber Dormancy and Sprouting in Potato.

Area of Science:

• Plant Physiology
• Biochemistry

Background:

• Nitric oxide (NO) plays a role in plant processes like seed dormancy release.
• The specific mechanism of NO in potato tuber dormancy remains largely uncharacterized.

Purpose of the Study:

• To elucidate the role of nitric oxide (NO) in regulating potato tuber dormancy and sprouting.
• To investigate the involvement of nitric oxide synthase (NOS)-like and nitrate reductase (NR) in NO production and its effect on dormancy.

Main Methods:

• Application of sodium nitroprusside (SNP) as an exogenous NO donor and c-PTIO as an NO scavenger.
• Inhibition of NOS-like activity using N-nitro-L-arginine methyl ester and NR activity using tungstate.
• Quantification of NO and abscisic acid (ABA) levels.
• Analysis of gene expression related to ABA metabolism (StCYP707A1 and StNCED1).

Main Results:

• Exogenous NO application (SNP) rapidly broke tuber dormancy and promoted sprouting.
• NO scavenging (c-PTIO) and inhibition of NOS/NR activities repressed NO-mediated sprouting.
• SNP treatment decreased ABA content and increased NO levels, while c-PTIO did the opposite.
• NO influenced the expression of ABA metabolism genes, reducing ABA levels and disrupting the ABA/gibberellin acid (GA) balance.

Conclusions:

• Nitric oxide (NO) generated by NOS-like or NR controls potato tuber dormancy release and sprouting.
• The mechanism involves NO modulating abscisic acid (ABA) metabolism and signaling pathways in tuber buds.
• This study clarifies the crucial role of NO in potato tuber physiology.