scholarly journals Nitric Oxide Is Involved in the Regulation of the Ascorbate–Glutathione Cycle Induced by the Appropriate Ammonium: Nitrate to Mitigate Low Light Stress in Brassica pekinensis

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 489 ◽  
Author(s):  
Linli Hu ◽  
Yutong Li ◽  
Yue Wu ◽  
Jian Lv ◽  
Mohammed Mujitaba Dawuda ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Light Intensity ◽  
Ammonium Nitrate ◽  
Chinese Cabbage ◽  
Light Stress ◽  
Ascorbate Oxidase ◽  
Monodehydroascorbate Reductase ◽  
Low Light ◽  
Low Light Intensity ◽  
Low Light Stress

Low light intensity is common in northern China due to fog or haze, and causes stress for crop plants. To solve the problem of low light intensity stress on the growth and development of vegetable crops in China, new cropping strategies must be developed. We previously showed that an appropriate ratio of ammonium and nitrate (NH4+:NO3−) can alleviate the effect of low light stress on plants, although it is not clear what mechanism is involved in this alleviation. We propose the hypothesis that an appropriate ammonium/nitrate ratio (10:90) can induce NO synthesis to regulate the AsA-GSH cycle in mini Chinese cabbage seedlings under low light intensity. To test the hypothesis, we conducted a series of hydroponic experiments. The results indicated that, under low light intensity conditions, appropriate NH4+:NO3− (N, NH4+:NO3− = 10:90) decreased the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2−) in leaves compared with nitrate treatment. Exogenous nitric oxide (SNP) had the same effects on MDA, H2O2, and O2−. However, with the addition of a NO scavenger (hemoglobin, Hb) and NO inhibitors (N-nitro-l-arginine methyl ester, L-NAME), NaN3 (NR inhibitor) significantly increased the contents of MDA, H2O2, and O2-. The application of N solution enhanced the AsA-GSH cycle by increasing the activities of ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and ascorbate oxidase (AAO), compared with control (NH4+:NO3− = 0:100). Meanwhile, exogenous SNP significantly increased the above indicators. All these effects of N on AsA-GSH cycle were inhibited by the addition of Hb, L-NAME and NaN3 in N solution. The results also revealed that the N and SNP treatments upregulated the relative expression level of GR, MDHAR1, APXT, DHAR2, and AAO gene in mini Chinese cabbage leaves under low light stress. These results demonstrated that the appropriate NH4+:NO3− (10:90) induced NO synthesis which regulates the AsA-GSH cycle in mini Chinese cabbage seedlings under low light stress.

Expression analysis of five candidate genes in eight contrasting rice genotypes suggest role of Lagging growth and development 1(LGD1), Pinhead1 (PNH1) and Leaf Panicle 2 (LP2) in low light intensity response at vegetative stage

2020 ◽  
Vol 57 (4) ◽  
pp. 261-270
Author(s):  
Suvendhu S Dutta ◽  
Wricha Tyagi ◽  
Mayank Rai
Keyword(s):  
Light Intensity ◽  
Candidate Genes ◽  
Light Stress ◽  
Vegetative Stage ◽  
Low Light ◽  
Expression Levels ◽  
Low Light Intensity ◽  
Rice Genotypes ◽  
Low Light Stress

Light acts as an energy source in plants for photosynthesis and also is an environmental cue leading to growth and differentiation. The quality and duration of light is therefore, key to obtaining yield and growth targets. Our previous study in rice led to identification of a panel of contrasting genotypes and putative candidate genes and markers for low light intensity tolerance. In the present study, expression of a set of five candidate genes (LGD1, PNH1, ILA1, CAB2R and LP2) previously identified to be associated with low light intensity tolerance was studied in a panel of eight rice genotypes at two time points post stress induction (one hour and two days). Cumulative normalised expression levels for genes LDG1 and PNH1 were down-regulated in response to one hour low light stress only in susceptible genotypes. While the cumulative normalised expression levels of ILA1 and LP2 genes were down- and up-regulated, respectively in tolerant genotypes. After two days of low light stress, expression of PNH1 and LP2 were down- and up-regulated in tolerant and susceptible genotypes, respectively. Our data suggests that genes LGD1, PNH1 and LP2 can be targeted for achieving vegetative stage low light intensity tolerance. Long term stress followed by recovery experiment revealed genotype Pusa Sugangh-5 as tolerant to low light intensity. These experiments suggest that mechanism of low light intensity tolerance in Pusa Sugangh-5 is distinct from the other four tolerant rice genotypes.

Effects of Light Intensity on Ear Differentiation of Barren-Stalk Defective Maize

2013 ◽  
Vol 726-731 ◽  
pp. 4864-4869 ◽  
Author(s):  
Xue Mei Zhong ◽  
Zhen Sheng Shi ◽  
Feng Hai Li ◽  
Hai Jiao Huang ◽  
Hai Yan Li
Keyword(s):  
Stress Intensity ◽  
Light Intensity ◽  
Light Stress ◽  
Inbred Lines ◽  
Young Female ◽  
Low Light ◽  
Intensity Range ◽  
Maize Genetic ◽  
The Relationship ◽  
Low Light Stress

Ear differentiation of different shade-resistance maize were studied under the shade stress using paired near isogenic, easy barren-stalk and not easy barren-stalk hybrids and inbred lines as test materials. The test verified the phenomenon of genetic defective barren stalk of maize preliminarily, revealed the relationship between barren stalk under the shade stress and ear differentiation and light intensity range inducing maize genetic defective barren stalk. Low light stress would make different varieties cause barren stalk and differences among varieties were obvious; easy barren stalk near-isogenic Shennong 98A was the most sensitive to low light stress and the stress intensity should be below 38% shade. Shade resistance of non-barren stalk near-isogenic Shennong 98B was close to normal inbred line Chang 7-2 and its intensity range of light stress were between 38%~60% shade; there were significant differences between hybrids of easy barren stalk D90, D80 and non-easy barren stalk Zheng Dan 958 under the 75% shade; shade stress could make young female ear short, grains per panicle reduce, the number of abortive grain increase and rates of barren stalk increase, which would aggravate with the increase of shade intensity and the reactions of easy barren stalk varieties were much more obvious, even caused 100% barren stalk led by female ear agenesis.

scholarly journals Exogenously applied 5-aminolevulinic acid mediated physiochemical regulations ameliorate weak light stress in tobacco seedlings

2019 ◽  
Vol 48 (2) ◽  
pp. 353-358
Author(s):  
Najia Li ◽  
Muhammad Shahid ◽  
Xuefeng Zong ◽  
Jun Lv ◽  
Daibin Wang ◽  
...  
Keyword(s):  
Light Intensity ◽  
Aminolevulinic Acid ◽  
Light Stress ◽  
Biomass Accumulation ◽  
Low Light ◽  
Chlorophyll Contents ◽  
Adverse Impacts ◽  
Low Light Intensity ◽  
Tobacco Seedlings ◽  
Weak Light

Experiments were conducted to study the deleterious impacts of low intensity light on physiochemical and agronomic attributes of tobacco, to evaluate varying doses of foliar 5-aminolevulinic acid (5-ALA) for alleviation of adverse impacts of low light intensity and to observe either 5-ALA modulated physiochemical regulations impart stress tolerance at agronomic level. Significant decrease of biomass accumulation, synthesis of osmo-protectants, chlorophyll contents, and chlorophyll fluorescence and increase in malondialdehyde were recorded compared to control. Exogenous application of 5-ALA excellently alleviated adverse impacts of low light intensity stress on agronomic and physiochemical attributes of tobacco seedlings. Conclusively, Light stress had adverse implications on all studied attributes while 5-ALA at 10-20 mg/l had remarkable alleviated deleterious impacts of light stress on plant.

scholarly journals Respon Karakter Morfo-Fisiologi Genotipe Tomat Senang Naungan Pada Intensitas Cahaya Rendah (The Respon of Morpho-Physiological Characters of Loving-Shade Genotypes at Low Light Intensity)

2019 ◽  
Vol 29 (1) ◽  
pp. 22
Author(s):  
Dwiwanti Sulistyowati ◽  
Muhammad Ahmad Chozin ◽  
Muhammad Syukur ◽  
Maya Melati ◽  
Dwi Guntoro
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Chlorophyll A ◽  
Light Stress ◽  
Leaf Number ◽  
Low Light ◽  
Fruit Number ◽  
Low Light Stress ◽  
Tomato Genotypes ◽  
Physiological Characters

<p>Tomat memiliki potensi untuk dikembangkan dengan sistem pertanaman berganda sebagai tanaman sela di bawah tegakan, baik di kehutanan, perkebunan, maupun pekarangan, sehingga mengalami stres cahaya rendah.  Stres cahaya rendah menyebabkan berbagai perubahan morfologi, anatomi dan fisiologi. Tujuan dari penelitian ini adalah untuk mempelajari karakter morfologi, anatomi dan fisiologi genotipe tomat pada intensitas cahaya rendah. Percobaan dilaksanakan di kebun percobaan Sekolah Tinggi Penyuluhan Pertanian (STPP) Bogor dari bulan Oktober 2014 sampai dengan Januari 2015. Percobaan menggunakan Rancangan Petak Tersarang (<em>nested design</em>) yang diulang tiga kali, faktor pertama terdiri atas dua taraf naungan, tanpa naungan (0%) dan naungan 50%. Faktor kedua berupa 50 genotipe tomat (ditapis menjadi 4 kelompok genotipe, yaitu senang, toleran, moderat dan peka naungan). Hasil penelitian menunjukkan bahwa genotipe tomat senang naungan mampu berproduksi lebih tinggi saat ternaungi, karena genotipe ini mampu beradaptasi lebih baik. Yaitu dengan cara meningkatkan tinggi tanaman, jumlah daun, luas daun, jumlah bunga dan jumlah buah dibandingkan genotipe peka. Terjadi peningkatan klorofil b lebih tinggi daripada klorofil a, sehingga terjadi penurunan yang lebih tinggi pada rasio klorofil a/b. Karakter yang berkorelasi dan berpengaruh langsung terhadap produksi tomat pada naungan 50% adalah luas daun, jumlah bunga, umur panen, rasio klorofil a/b, jumlah buah dan bobot per buah.</p><p><strong>Keywords</strong></p><p><strong></strong>Intensitas cahaya rendah; Karakter genotipe tomat</p><p><strong>ABSTRACT</strong></p><p>Tomatoes have the potential to be developed with multiple cropping systems as intercropping plants under stands, both in forestry, plantations, and yard, thus experiencing low light stress. Low light stress causes a variety of morphological, anatomical and physiological changes. The aim of this study was to investigate the morphological, anatomical and physiological characters of tomato genotypes at low light intensity. The experiments were conducted in the experimental field of Bogor Agricultural Extension Institute, in Bogor, from October 2014 to January 2015. The experiment was arranged in nested randomized design with two factors and three replication. The first factor consisted of two levels of shading intensity, i.e. without shade (0 %) and 50% shading. and the second factor was 50 tomato genotypes (4 groups of tomato genotypes, i.e. shade-loving, shade-tolerant, shade-moderate and shade-sensitive genotypes). The results showed that the shade-loving genotypes was capable of producing higher levels when shaded, as the genotype was able to adapt better. That was by increasing the plant height, leaf number, leaf area, flower number and fruit number compared to sensitive genotypes. Increased chlorophyll b is higher than chlorophyll a, resulting in a higher decrease in the ratio of chlorophyll a/b. Character that correlates and directly affects tomato production in 50% shade was leaf area, leaf number, harvesting time, a/b chlorophyll ratio, fruit number and fruit weight.</p>

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