ABSTRACT
Anthocyanins are natural pigments and play significant roles in multiple growth, development, and stress response processes in plants. The vegetables with high anthocyanin content have better colours, higher antioxidant activity than green vegetables and are potent antioxidants with health benefits. However, the mechanism of anthocyanin accumulation in purple and green leaves of Raphanus sativus (radish) is poorly understood and needs further investigation. In the present study, the pigment content in a green leaf cultivar "RA9" and a purple-leaf cultivar "MU17" was characterized and revealed that the MU17 had significantly increased accumulation of anthocyanins and reduced content of chlorophyll and carotenoid compared with that in RA9. Meanwhile, these two cultivars were subjected to a combination of metabolomic and transcriptome studies. A total of 52 massively content-changed metabolites and 3463 differentially expressed genes were discovered in MU17 compared with RA9. In addition, the content of significantly increased flavonoids (such as pelargonidin and cyanidin) was identified in MU17 compared to RA9 using an integrated analysis of metabolic and transcriptome data. Moreover, the quantitative real-time polymerase chain reaction results also confirmed the differences in the expression of genes related to pathways of flavonoids and anthocyanin metabolism in MU17 leaves. The present findings provide valuable information for anthocyanin metabolism and further genetic manipulation of anthocyanin biosynthesis in radish leaves. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01245-w.
ABSTRACT
A time-domain ranging algorithm is proposed for a frequency-modulated continuous wave (FMCW) short-range radar sensor with high accuracy and low complexity. The proposed algorithm estimates the distance by calculating the ratio of the beat frequency signal to its derivative and thereby eliminates the restriction of frequency bandwidth on ranging accuracy. Meanwhile, we provide error analysis of the proposed algorithm under different distances, integral lengths, relative velocities, and signal-to-noise ratios (SNRs). Finally, we fabricate FMCW sensor prototype and construct a measurement system. Testing results demonstrate that the proposed time-domain algorithm could achieve range error within 0.8 m. Compared with the conventional fast Fourier transform (FFT) estimation scheme, the proposed method performs ranging without the requirement of complex multiplications, which makes it reasonable to be implemented in real-time and low-cost systems.
