Search for: All records

Plant growth-promoting bacteria (PGPB) can be incorporated in biofertilizer formulations, which promote plant growth in different ways, such as fixing nitrogen and producing phytohormones and nitric oxide (NO). NO is a free radical involved in the growth and defense responses of plants and bacteria. NO detection is vital for further investigation in different agronomically important bacteria. NO production in the presence of KNO3 was evaluated over 1–3 days using eight bacterial strains, quantified by the usual Griess reaction, and monitored by 2,3-diaminonaphthalene (DAN), yielding 2,3-naphthotriazole (NAT), as analyzed by fluorescence spectroscopy, gas chromatography–mass spectrometry, and high-performance liquid chromatography. The Greiss and trapping reaction results showed that Azospirillum brasilense (HM053 and FP2), Rhizobium tropici (Br322), and Gluconacetobacter diazotrophicus (Pal 5) produced the highest NO levels 24 h after inoculation, whereas Nitrospirillum amazonense (Y2) and Herbaspirillum seropedicae (SmR1) showed no NO production. In contrast to the literature, in NFbHP–NH4Cl–lactate culture medium with KNO3, NO trapping led to the recovery of a product with a molecular mass ion of 182 Da, namely, 1,2,3,4-naphthotetrazole (NTT), which contained one more nitrogen atom than the usual NAT product with 169 Da. This strategy allows monitoring and tracking NO production in potential biofertilizing bacteria, providing future opportunities to better understand the mechanisms of bacteria–plant interaction and also to manipulate the amount of NO that will sustain the PGPB. 

Studies have previously shown that anthracene and naphthalene derivatives serve as compounds for trapping and chemically generating singlet molecular oxygen [O 2 ( 1 Δ g )], respectively. Simple and efficient synthetic routes to anthracene and naphthalene derivatives are needed, for improved capture and release of O 2 ( 1 Δ g ) in cellular environments. Because of this need, we have synthesized a dihydroxypropyl amide naphthlene endoperoxide as a O 2 ( 1 Δ g ) donor, as well as five anthracene derivatives as O 2 ( 1 Δ g ) acceptor. The anthracene derivatives bear dihydroxypropyl amide, ester, and sulfonate ion end groups connected to 9,10-positions by way of unsaturated (vinyl) and saturated (ethyl) bridging groups. Heck reactions were found to yield these six compounds in easy-to-carry out 3-step reactions in yields of 50–76%. Preliminary results point to the potential of the anthracene compounds to serve as O 2 ( 1 Δ g ) acceptors and would be amenable for future use in biological systems to expand the understanding of O 2 ( 1 Δ g ) in biochemistry.