Comparative Characterization of Aroma Volatiles and Related Gene Expression Analysis at Vegetative and Mature Stages in Basmati and Non-Basmati Rice (Oryza sativa L.) Cultivars.
Aroma volatiles in Basmati-370, Ambemohar-157 (non-basmati scented), and IR-64 (non-scented) rice cultivars were qualitatively and quantitatively analyzed at vegetative and maturity stages to study their differential accumulation using headspace solid-phase microextraction, followed by gas chromatography mass spectrometry (HS-SPME-GCMS) with selected ion monitoring (SIM) approach. In addition, expression analysis of major aroma volatile 2-acetyl-1-pyrroline (2AP)-related genes, betaine aldehyde dehydrogenase 2 (badh2) and Δ(1)-pyrolline-5-carboxylic acid synthetase (P5CS), were studied by real-time PCR. Maximum number of volatiles recorded at vegetative (72-58) than at mature stage (54-39). Twenty new compounds (12 in scented and 8 in both) were reported in rice. N-containing aromatic compounds were major distinguishing class separating scented from non-scented. Among quantified 26 volatiles, 14 odor-active compounds distinguished vegetative and mature stage. Limit of detection (LOD) and limit of quantification (LOQ) for 2AP was 0.001 mg/kg of 2AP and 0.01 g of rice, respectively. 2AP accumulation in mature grains was found three times more than in leaves of scented rice. Positive correlation of 2AP with 2-pentylfuran, 6-methyl-5-hepten-2-one, and (E)-2-nonenal suggests their major role as aroma contributors. The badh2 expression was inversely and P5CS expression was positively correlated with 2AP accumulation in scented over non-scented cultivar.
Department of Botany, Savitribai Phule Pune University, Pune, 411007, India.|Department of Plant Biochemistry and Molecular Biology, Vilasrao Deshmukh College of Agricultural Biotechnology, Latur, VNMKV, Parbhani, 413512, India.
Vidya
V
Hinge
Department of Plant Biochemistry and Molecular Biology, Vilasrao Deshmukh College of Agricultural Biotechnology, Latur, VNMKV, Parbhani, 413512, India.
Hemant
H
Patil
Department of Botany, Savitribai Phule Pune University, Pune, 411007, India. abnadaf@unipune.ac.in.
Altafhusain
A
Nadaf
D008401:Gas Chromatography-Mass Spectrometry; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D057230:Limit of Detection; D009812:Odorants; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D052617:Solid Phase Microextraction; D014835:Volatilization
2-Acetyl-1-pyrroline; Growth stages; HS-SPME-GCMS; P5CS; badh2