Predicting the Photosynthesis Rate of Rice Leaves under Fluctuating Light Using LSTM

The paper presents an example of the linear splines use to describe the photosynthesis light curves for microalgae culture. The main mathematical models of the relationship between photosynthesis rate and light are listed. Based on the previously formulated basic principles of modeling microalgae photobiosynthesis, a mathematical model is proposed that describes the dependence of the assimilation number of chlorophyll a on the value of the light flux by linear splines. The advantage of the proposed approach is a clear definition of the point of change of the limiting factor. It is shown that light-limited photosynthesis rate is determined not only by external irradiation, but also by the concentration of chlorophyll a. The light-saturated rate depends on the amount of a key enzyme complex, which limits the rate of energy exchange reactions in the cell. Verification of the proposed model on the example of the diatom microalgae Skeletonema costatum was carried out. It is shown that the higher the degree of cell adaptation to high irradiation, the better the photosynthesis curve is described by linear splines. If S. costatum cells are adapted to low irradiation, deviations of experimental data from the idealized broken line are observed, which are caused by changes in the pigment composition. When the experimental data are normalized, the cell adaptation factor is reduced, all points are described by a single broken line, which indicates the universality of the proposed approach.

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Expression Analysis of Pathogenesis-related 1 Proteins in Normal Growth of Rice Leaves and Interactions Between Rice and Xan-thomonas oryzaepv.oryzae

CHINESE BULLETIN OF BOTANY ◽

10.3724/sp.j.1259.2014.00127 ◽

2014 ◽

Vol 49 (2) ◽

pp. 127 ◽

Cited By ~ 1

Author(s):

Li Xuejiao ◽

Fan Wei ◽

Niu Dongdong ◽

Guan Mingli ◽

Miao Liuyang ◽

...

Keyword(s):

Expression Analysis ◽

Normal Growth ◽

Pathogenesis Related ◽

Rice Leaves

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Nitrogen Volatilization from Rice Leaves. I. Effects of Genotype and Air Temperature 1

Crop Science ◽

10.2135/cropsci1981.0011183x002100040030x ◽

1981 ◽

Vol 21 (4) ◽

pp. 596-600 ◽

Cited By ~ 14

Author(s):

C. A. Stutte ◽

P. R. F. Silva

Keyword(s):

Air Temperature ◽

Rice Leaves

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Comprehensive model of microalgae photosynthesis rate as a function of culture conditions in photobioreactors

Applied Microbiology and Biotechnology ◽

10.1007/s00253-013-5035-2 ◽

2013 ◽

Vol 97 (17) ◽

pp. 7627-7637 ◽

Cited By ~ 70

Author(s):

T. A. Costache ◽

F. Gabriel Acién Fernández ◽

M. M. Morales ◽

J. M. Fernández-Sevilla ◽

I. Stamatin ◽

...

Keyword(s):

Culture Conditions ◽

Photosynthesis Rate ◽

Comprehensive Model

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The Coordinated Upregulated Expression of Genes Involved in MEP, Chlorophyll, Carotenoid and Tocopherol Pathways, Mirrored the Corresponding Metabolite Contents in Rice Leaves during De-Etiolation

Plants ◽

10.3390/plants10071456 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1456

Author(s):

Xin Jin ◽

Can Baysal ◽

Margit Drapal ◽

Yanmin Sheng ◽

Xin Huang ◽

...

Keyword(s):

Higher Plants ◽

Expression Patterns ◽

Regulatory Elements ◽

Isoprenoid Biosynthesis ◽

Promoter Regions ◽

Expression Of Genes ◽

Coordinated Expression ◽

Rice Leaves ◽

Mechanistic Basis ◽

Phosphate Synthase

Light is an essential regulator of many developmental processes in higher plants. We investigated the effect of 4-hydroxy-3-methylbut-2-enyl diphosphate reductase 1/2 genes (OsHDR1/2) and isopentenyl diphosphate isomerase 1/2 genes (OsIPPI1/2) on the biosynthesis of chlorophylls, carotenoids, and phytosterols in 14-day-old etiolated rice (Oyza sativa L.) leaves during de-etiolation. However, little is known about the effect of isoprenoid biosynthesis genes on the corresponding metabolites during the de-etiolation of etiolated rice leaves. The results showed that the levels of α-tocopherol were significantly increased in de-etiolated rice leaves. Similar to 1-deoxy-D-xylulose-5-phosphate synthase 3 gene (OsDXS3), both OsDXS1 and OsDXS2 genes encode functional 1-deoxy-D-xylulose-5-phosphate synthase (DXS) activities. Their expression patterns and the synthesis of chlorophyll, carotenoid, and tocopherol metabolites suggested that OsDXS1 is responsible for the biosynthesis of plastidial isoprenoids in de-etiolated rice leaves. The expression analysis of isoprenoid biosynthesis genes revealed that the coordinated expression of the MEP (2-C-methyl-D-erythritol 4-phosphate) pathway, chlorophyll, carotenoid, and tocopherol pathway genes mirrored the changes in the levels of the corresponding metabolites during de-etiolation. The underpinning mechanistic basis of coordinated light-upregulated gene expression was elucidated during the de-etiolation process, specifically the role of light-responsive cis-regulatory motifs in the promoter region of these genes. In silico promoter analysis showed that the light-responsive cis-regulatory elements presented in all the promoter regions of each light-upregulated gene, providing an important link between observed phenotype during de-etiolation and the molecular machinery controlling expression of these genes.

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Sunfleck properties from time series of fluctuating light

Agricultural and Forest Meteorology ◽

10.1016/j.agrformet.2021.108554 ◽

2021 ◽

Vol 308-309 ◽

pp. 108554

Author(s):

Maxime Durand ◽

Baiba Matule ◽

Alexandra J. Burgess ◽

T. Matthew Robson

Keyword(s):

Time Series ◽

Fluctuating Light

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Shading Effects on Leaf Gas Exchange, Leaf Pigments and Secondary Metabolites of Polygonum minus Huds., an Aromatic Medicinal Herb

Plants ◽

10.3390/plants10030608 ◽

2021 ◽

Vol 10 (3) ◽

pp. 608

Author(s):

Fairuz Fatini Mohd Yusof ◽

Jamilah Syafawati Yaacob ◽

Normaniza Osman ◽

Mohd Hafiz Ibrahim ◽

Wan Abd Al Qadr Imad Wan-Mohtar ◽

...

Keyword(s):

Gas Exchange ◽

Secondary Metabolites ◽

Chlorophyll A ◽

Leaf Gas Exchange ◽

Photosynthesis Rate ◽

Total Phenolic ◽

Chlorophyll B ◽

Low Light ◽

Total Anthocyanin ◽

Polygonum Minus

The growing demand for high value aromatic herb Polygonum minus-based products have increased in recent years, for its antioxidant, anticancer, antimicrobial, and anti-inflammatory potentials. Although few reports have indicated the chemical profiles and antioxidative effects of Polygonum minus, no study has been conducted to assess the benefits of micro-environmental manipulation (different shading levels) on the growth, leaf gas exchange and secondary metabolites in Polygonum minus. Therefore, two shading levels (50%:T2 and 70%:T3) and one absolute control (0%:T1) were studied under eight weeks and 16 weeks of exposures on Polygonum minus after two weeks. It was found that P. minus under T2 obtained the highest photosynthesis rate (14.892 µmol CO2 m−2 s−1), followed by T3 = T1. The increase in photosynthesis rate was contributed by the enhancement of the leaf pigments content (chlorophyll a and chlorophyll b). This was shown by the positive significant correlations observed between photosynthesis rate with chlorophyll a (r2 = 0.536; p ≤ 0.05) and chlorophyll b (r2 = 0.540; p ≤ 0.05). As the shading levels and time interval increased, the production of total anthocyanin content (TAC) and antioxidant properties of Ferric Reducing Antioxidant Power (FRAP) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) also increased. The total phenolic content (TPC) and total flavonoid content (TFC) were also significantly enhanced under T2 and T3. The current study suggested that P.minus induce the production of more leaf pigments and secondary metabolites as their special adaptation mechanism under low light condition. Although the biomass was affected under low light, the purpose of conducting the study to boost the bioactive properties in Polygonum minus has been fulfilled by 50% shading under 16 weeks’ exposure.

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Phytochemical Analysis and Potential Biological Activities of Essential Oil from Rice Leaf

Molecules ◽

10.3390/molecules24030546 ◽

2019 ◽

Vol 24 (3) ◽

pp. 546 ◽

Cited By ~ 3

Author(s):

Truong Minh ◽

Tran Xuan ◽

Truong Van ◽

Yusuf Andriana ◽

Tran Viet ◽

...

Keyword(s):

Mass Spectrometry ◽

Essential Oil ◽

Atmospheric Pressure Chemical Ionization ◽

Biological Activities ◽

Methyl Ricinoleate ◽

Gas Chromatography Mass Spectrometry ◽

Phytochemical Analysis ◽

Chemical Compositions ◽

Rice Leaf ◽

Rice Leaves

Although many investigations on phytochemicals in rice plant parts and root exudates have been conducted, information on the chemical profile of essential oil (EO) and potent biological activities has been limited. In this study, chemical compositions of rice leaf EO and in vitro biological activities were investigated. From 1.5 kg of fresh rice leaves, an amount of 20 mg EO was obtained by distillation and analyzed by gas chromatography-mass spectrometry (GC-MS), electrospray ionization (ESI), and atmospheric pressure chemical ionization (APCI) to reveal the presence of twelve volatile constituents, of which methyl ricinoleate (27.86%) was the principal compound, followed by palmitic acid (17.34%), and linolenic acid (11.16%), while 2-pentadecanone was the least (2.13%). Two phytoalexin momilactones A and B were first time identified in EO using ultra-performance liquid chromatography coupled with electrospray mass spectrometry (UPLC/ESI-MS) (9.80 and 4.93 ng/g fresh weight, respectively), which accounted for 7.35% and 3.70% of the EO, respectively. The assays of DPPH (IC50 = 73.1 µg/mL), ABTS (IC50 = 198.3 µg/mL), FRAP (IC50 = 700.8 µg/mL) and β-carotene oxidation (LPI = 79%) revealed that EO possessed an excellent antioxidant activity. The xanthine oxidase assay indicated that the anti-hyperuricemia potential was in a moderate level (IC50 = 526 µg/mL) as compared with the standard allopurinol. The EO exerted potent inhibition on growth of Raphanus sativus, Lactuca sativa, and two noxious weeds Echinochloa crus-galli, and Bidens pilosa, but in contrast, the growth of rice seedlings was promoted. Among the examined plants, the growth of the E. crus-galli root was the most inhibited, proposing that constituents found in EO may have potential for the control of the problematic paddy weed E. crus-galli. It was found that the EO of rice leaves contained rich phytochemicals, which were potent in antioxidants and gout treatment, as well as weed management. Findings of this study highlighted the potential value of rice leaves, which may provide extra benefits for rice farmers.

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