Hubungan Aktivitas Nitrat Reduktase dan Kadar Klorofil Kultivar Kedelai Tahan Kekeringan

Agrotek ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Ivonne Fitri Mariay

<em>Plants suffering from drought stress can be indicated by the changing of character on the morphology, anatomy and physiology, characterized by inhibition of leaf growth, accelerated root growth, stomata closure and leaf curly. Cultivars that are tolerance to drought can physiologically adapted by increasing prolin level reduce the osmotic potential in order to maintain turgor in the condition of low tissue water potential. The research was aimed to study the physiological characters of drought tolerant soybean cultivar of determine the relationship of nitrate reductase activity and chlorophyll content of drought-tolerance cultivars and susceptible to drought stress conditions. The research was conducted at Tridharma Garden Agricultural Faculty of Gadjah Mada University, Banguntapan, Bantul, Daerah Istimewa Yogyakarta from January to March 2012. The experiment was arranged on Factorial Complete Block Design with three replications. The first factor was soybean cultivar consist of five levels those are Wilis (drought tolerance), Tidar (drought tolerant), Gema (drought tolerant), Grobogan (susceptible) and Argomulyo (susceptible). The second factor was watering interval consist of four levels which were watering once a day, every 2 days, every 4 days and every 8 days. Drought stress treatment begans at 24 DAP. Parameters observed were moisture content, nitrate reductase activity, chlorophyll a, chlorophyll b, and total of chlorophyll at 56 DAP. Portable data analysis using SAS 9.1. for windows. The results showed that nitrate reductase activity contributes to greater levels of chlorophyll of drought tolerance cultivars "Wilis", "Tidar" and "Gema" on the conditions of drought stress than the susceptible cultivar "Grobogan" and "Argomulyo".</em>

2021 ◽  
Author(s):  
Juby BABY ◽  
Minimol Janakyseifudeen ◽  
Suma Basura ◽  
Santhoshkumar Adiyodi Venugopal ◽  
Jiji Joseph ◽  
...  

Abstract Background:Cocoa, being a shade loving crop cannot withstand long periods of water stress. Breeding for drought tolerance is the need of the hour due to change in climatic condition and extension of crop to non traditional area. Hybrids were produced by crossing four tolerant genotypes in all possible combination. The cross GVI 55 x M 13.12 didn’t yield any fruit due to cross incompatibility between these genotypes. Various biochemical parameters act as the true indicators to select tolerant and susceptible types. The major biochemical parameters considered after imposing stress included proline, nitrate reductase activity, superoxide dismutase content and glycine betaine. Results: The drought tolerant hybrids were having high amount of proline, superoxide dismutase enzyme and glycine betaine content. Normally, plants having drought stress shows low amount of nitrate reductase activity. However, in case of hybrids, the drought tolerant hybrids were having higher NR activity than the susceptible hybrids. The highest amount of NR was found in the control plants kept at fully irrigated conditions.Conclusions: This experiment showed the role of different biochemical enzymes and osmolytes in giving tolerance to plants during drought stress. Logistic regression analysis selected proline and nitrate reductase as the two biochemical markers for identifying efficient drought tolerant genotypes in the future breeding programmes.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Baby Juby ◽  
Janaki Seifudeen Minimol ◽  
Basura Suma ◽  
Adiyodi Venugopal Santhoshkumar ◽  
Joseph Jiji ◽  
...  

Abstract Background Cocoa, being a shade loving crop cannot withstand long periods of water stress. Breeding for drought tolerance is the need of the hour due to change in climatic condition and extension of crop to non-traditional areas. Hybrids were produced by crossing four tolerant genotypes in all possible combination. The cross GV1 55 x M 13.12 didn’t yield any fruit due to cross incompatibility between these genotypes. Various biochemical parameters act as the true indicators to select tolerant and susceptible types. The major biochemical parameters considered after imposing stress included proline, nitrate reductase activity, superoxide dismutase content and glycine betaine. Results The drought tolerant hybrids were having high amount of proline, superoxide dismutase enzyme and glycine betaine content. Normally, plants having drought stress show low amount of nitrate reductase activity. However, in case of hybrids, the drought tolerant hybrids were having higher NR activity than the susceptible hybrids. The highest amount of NR was found in the control plants kept at fully irrigated conditions. Conclusions This experiment showed the role of different biochemical enzymes and osmolytes in giving tolerance to plants during drought stress. Logistic regression analysis selected proline and nitrate reductase as the two biochemical markers for identifying efficient drought tolerant genotypes in the future breeding programmes.


Weed Science ◽  
1973 ◽  
Vol 21 (6) ◽  
pp. 561-564 ◽  
Author(s):  
Donald S. Galitz

Nitrate reductase activity of seed leaves and the first three true leaves of tall morningglory [Ipomoea purpurea (L.) Roth] was shown to increase rapidly initially then gradually decrease. The greatest level of reductase activity of each true leaf was reached at the fourth to fifth day after unfolding. A subsequent leveling off of enzyme activity corresponded to the acceleration of leaf growth. Leaf nitrates were correlated with enzyme activity. The sum of leaf activities was used to estimate the total reductive capacity of the plant leaf tissue at each sampling date.


2010 ◽  
Vol 34 (3) ◽  
pp. 801-809 ◽  
Author(s):  
José Lavres Junior ◽  
João de Deus Gomes dos Santos Junior ◽  
Francisco Antonio Monteiro

Nitrogen and K deficiency are among the most yield limiting factors in Brazilian pastures. The lack of these nutrients can hamper the chlorophyll biosynthesis and N content in plant tissues. A greenhouse experiment was carried out to evaluate the relationship among N and K concentrations, the indirect determination of chlorophyll content (SPAD readings), nitrate reductase activity (RNO3-) in newly expanded leaf lamina (NL) and the dry matter yield for plant tops of Mombaça grass (Panicum maximum Jacq.). A fractionated 5² factorial design was used, with 13 combinations of N and K rates in the nutrient solution. The experimental units were arranged in a randomized block design, with four replications. Plants were harvested twice. The first harvest occurred 36 days after seedling transplanting and the second 29 days after the first. Significance occurred for the interaction between the N and K rates to SPAD readings and to RNO3- assessment taken on the NL during the first growth. Besides, RNO3- and SPAD readings increased only with the NL N concentration, reaching the highest values of both variables up to about 25 g kg-1, but were ratively constant at higher leaf N. Significant relationships either between SPAD readings or RNO3- activity and shoot dry mass weight were also observed. The critical levels of N concentration in the NL were, respectively, 22 and 17g kg-1 in the first and second harvest. Thus, SPAD instrument and RNO3- assessment can be used as complementary tools to evaluate the N status in forage grass.


2019 ◽  
Vol 87 (1) ◽  
Author(s):  
Dian Mutiara AMANAH ◽  
Nurhaimi HARIS ◽  
Laksmita Prima SANTI

Silica (Si) in the form of soluble silicic acid [H4SiO4] was an element that makes plants more resistant to drought stress through biochemical or molecular processes and contributing to growth stimulation under biotic and abiotic stress conditions. The objective of this study was to determine the response of oil palm seedlings to drought stress by the bio-Si application. The experiment was arranged in complete random design (CRD) with ten replicates.  Bio-Si was developed in solid and liquid forms with a dissolved Si content at least 10% (w/v). The eight combinations of solid bio-Si application per seedling were: (i) blank (without fertilizers), (ii) 5 g NPK 15-15-15, (iii) 5 g NPK 15-15-15 + 109cfu of Si-solubilizing microbes (SSM), (iv-viii) 5 g NPK 15-15-15 + 2.5; 5.0; 7.5; 10 g bio-Si; and 5 g Na2SiO3.  On the other hand, liquid bio-Si application per seedling were: (i) blank (without fertilizers), (ii) 5 g NPK 15-15-15, (iii) 5 g NPK 15-15-15 + 109cfu of SSM, (iv-viii) 5 g NPK 15-15-15 + 25 mL; 50 mL; 75 mL; 100 mL bio-Si; and 50 mL Na2SiO3. Drought stress tolerance was analyzed by using proline concentration, nitrate reductase activity (NRA), chlorophyll content, and stomatal closure in the leave of oil palm seedlings. Based on the physiological response, this research indicates that bio-Si application could induce seedling tolerance to drought stress. The bio-Si treatments gave a positive response of proline concentration, nitrate reductase activity (NRA), chlorophyll content, and stomatal closure. The doses of 5 g NPK 15-15-15 + 7.5 g solid bio-Si and 5 g NPK 15-15-15 + 75 mL liquid bio-Si per seedling were a recommended to increase oil palm seedlings tolerance to drought stress.[Key words: bio-Si, chlorophyll, nitrate reductase activity, Si-solubilizing microbes]. AbstrakSilika (Si) dalam bentuk terlarut asam silikat [H4SiO4]merupakan unsur yang dapat menyebabkan tanaman lebih tahan terhadap cekaman kekeringan melalui proses biokimia atau molekuler dan menstimulasi pertumbuhan dalam kondisi cekaman biotik dan abiotik. Tujuan dari penelitian ini adalah mengetahui respons fisiologi bibit kelapa sawit yang diberi bio-Si terhadap cekaman kekeringan. Penelitian didesain dengan rancangan acak lengkap (RAL) dan sepuluh ulangan. Bio-Si dikembangkan dalam bentuk padat dan cair dengan kadar Si terlarut minimal 10 % (b/v). Delapan aplikasi bio-Si padat per bibit adalah: (i) blanko (tanpa pupuk), (ii) 5 g NPK 15-15-15, (iii) 5 g NPK 15-15-15 + 109cfu mikrob pelarut silika, (iv-viii) 5 g NPK 15-15-15 + 2,5 g; 5,0 g; 7,5 g; 10 g bio-Si, dan 5 g Na2SiO3. Sementara untuk aplikasi bio-Si cair per bibit adalah: (i) blanko (tanpa pupuk), (ii) 5 g NPK 15-15-15, (iii) 5 g NPK  15-15-15 + 109cfu mikroorganisme pelarut silika (MPS), (iv-viii) 5 g NPK 15-15-15 + 25 ml; 50 ml; 75 ml; dan 100 mLbio-Si, dan 50 ml Na2SiO3. Pengamatan yang dilakukan meliputi analisis prolin, aktivitas nitrat reduktase (ANR), kandungan klorofil, serta morfologi stomata pada daun bibit kelapa sawit. Berdasarkan data fisiologi yang diperoleh dari kegiatan penelitian ini, aplikasi bio-Si dapat meningkatkan ketahanan bibit kelapa sawit terhadap cekaman kekeringan. Perlakuan bio-Si memberikan respon positif terhadap konsentrasi prolin,aktivitas nitrat reduktase (ANR), kandungan klorofil, serta morfologi stomata.Dosis 5 g NPK 15-15-15 + 7,5 g bio-Si padat dan 5 g NPK 15-15-15 + 75 mLbio-Si cair dapat direkomendasikan untuk meningkatkan ketahanan bibit kelapa sawit terhadap cekaman kekeringan.  [Kata kunci: bio-Si, klorofil, aktivitas nitrat reduktase, mikroorganisme pelarut silika].


Author(s):  
Savyata Kandel

Wheat (Triticum aestivum L.) is one of the major basic stable crops grown worldwide, however, it is sensitive to environmental stresses like drought. With climate change, drought stress is becoming an increasingly severe constraint on wheat production which affects the plant growth and development, physiological functions, grain formation, grain quality and ultimately the yield. Various responses including biochemical, physiological, morphological, and molecular adaptations are shown by plants to survive in the drought stress condition. Drought escape, avoidance and tolerance are important coping mechanisms of wheat plant under drought environment. Several mechanisms such as accumulation of ABA, osmotic adjustment, and induction of dehydrins may confer drought tolerance by maintaining the high tissue water potential. As the root structure and root biomass define the pattern of water extraction from the soil, enhanced root and suppressed shoot growth resulting in higher root: shoot ratio facilitated plants to drought tolerance. The development of drought tolerance varieties becomes an important due to the uneven distribution of rainfall and water shortage. Some growth stage-specific physio-morphological traits are fundamental targets to breed drought-tolerant wheat varieties. Mutation breeding, molecular breeding, genome engineering techniques including gene pyramiding, gene stacking, and transgenics are employed to breed wheat for tolerance to abiotic stresses including drought. Omics decode the entire genome to have better understanding of plant molecular responses that will provide precise strategies for crop improvement. This paper discusses the wheat plant’s responses to drought stress, their defense mechanisms and modern techniques for the development of drought tolerant wheat varieties.


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