Abstract

Nitric oxide (NO) is a bioactive molecule that functions in numerous physiological processes in plants, most of them involving cross-talk with traditional phytohormones. Auxin is the main hormone that regulates root system architecture. In this communication we report that NO promotes lateral root (LR) development, an auxin-dependent process. Application of the NO donor sodium nitroprusside (SNP) to tomato ( Lycopersicon esculentum Mill.) seedlings induced LR emergence and elongation in a dose-dependent manner, while primary root (PR) growth was diminished. The effect is specific for NO since the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO) blocked the action of SNP. Depletion of endogenous NO with CPTIO resulted in the complete abolition of LR emergence and a 40% increase in PR length, confirming a physiological role for NO in the regulation of root system growth and development. Detection of endogenous NO by the specific probe 4,5-diaminofluorescein diacetate (DAF-2 DA) revealed that the NO signal was specifically located in LR primordia during all stages of their development. In another set of experiments, SNP was able to promote LR development in auxin-depleted seedlings treated with the auxin transport inhibitor N-1-naphthylphthalamic acid (NPA). Moreover, it was found that LR formation induced by the synthetic auxin 1-naphthylacetic acid (NAA) was prevented by CPTIO in a dose-dependent manner. All together, these results suggest a novel role for NO in the regulation of LR development, probably operating in the auxin signaling transduction pathway.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.