scholarly journals Low temperature and hardening effects on photosynthetic apparatus efficiency and survival of forage grass varieties

2014 ◽  
Vol 60 (No. 4) ◽  
pp. 177-183 ◽  
Author(s):  
B. Borawska-Jarmułowicz ◽  
G. Mastalerczuk ◽  
S. Pietkiewicz ◽  
Kalaji MH
Keyword(s):  
Chlorophyll Fluorescence ◽  
Freezing Tolerance ◽  
Positive Impact ◽  
Photosynthetic Apparatus ◽  
Extreme Temperature ◽  
Temperature Treatment ◽  
Developmental Phase ◽  
Strongly Correlated ◽  
Perennial Plants ◽  
Psii Activity

Freezing tolerance is essential for perennial plants and ability to adapt to extreme temperature is crucial for their survival in many environments. Freezing tolerance of hardened and unhardened plants of Dactylis glomerata and Lolium perenne varieties was probed by their quantum photosynthetic efficiency using the chlorophyll fluorescence technique. Quantum yield of photosystem II (PSII) electron transport (&Phi;<sub>PSII</sub>), maximal (F<sub>m</sub>&rsquo;) and steady-state (F<sub>s</sub>) chlorophyll fluorescence yields of light-adapted samples were measured. &Phi;<sub>PSII</sub> depended on developmental phase, temperature and hardening process. A clear decline in PSII activity, especially after &ndash;10&deg;C application was observed. Plant hardening during emergence phase had a positive impact on PSII activity, especially after &ndash;5&deg;C application. After 72 h of &ndash;5&deg;C temperature treatment, hardened plants showed quicker recovery of their photosynthetic apparatus (0.527&ndash;0.697) as compared to unhardened ones (0.224&ndash;0.330). Stress temperature of &ndash;10&deg;C caused irreversible changes of photosynthetic apparatus of hardened and unhardened plants independently of growth phases (0.003&ndash;0.014). &Phi;<sub>PSII</sub> and F<sub>m</sub>&rsquo; parameters were strongly correlated with shoots survival under stress. Our results suggest that perennial plants&rsquo; hardening allows them to survive low temperatures due inter alia enhancing their photosynthetic machinery performance.

scholarly journals Improvement of the photosynthetic activity of Moldavian dragonhead (Dracocephalum moldavica L.) through foliar application of a nitrophenolate–based biostimulant

2018 ◽  
Vol 10 ◽  
pp. 01009
Author(s):  
Sławomir Kocira ◽  
Agnieszka Sujak ◽  
Tomasz Oniszczuk ◽  
Agnieszka Szparaga ◽  
Mariusz Szymanek ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Photosynthetic Activity ◽  
Foliar Application ◽  
Positive Impact ◽  
Abiotic Stress Tolerance ◽  
Photosynthetic Apparatus ◽  
Nutrient Content ◽  
Physiological Processes ◽  
Naturally Occurring ◽  
Reported Study

Application of biostimulants instigates many physiological processes that enhance nutrition efficiency, abiotic stress tolerance, and quality traits of crops, regardless of their nutrient content. One of such preparations is Atonik which contains nitrophenol compounds naturally occurring in plant cells. Several studies have confirmed its beneficial effect on the growth, development, and improved metabolic activity of plants. Therefore, it seems advisable to investigate the effect of Atonik preparation on the photosynthetic activity of Moldavian dragonhead (Dracocephalum moldavica L.). The reported study was carried out in 2014 in Perespa, Poland. Over the growing season, Atonik was foliar-applied at a dose of 0.3 L/ha (0.1%) and 0.6 L/ha (0.2%) by single and double spraying of plants. Chlorophyll content and nitrogen status (N) were estimated by a Chlorophyll Meter SPAD-502 Plus. The foliar application of Atonik was found to improve the efficiency of the photosynthetic apparatus and chlorophyll content in the leaves of Dracocephalum moldavica plants, but the results were dependent on biostimulant concentration and number of its applications, and on the date of measurement. To conclude, Atonik is an environmental-friendly preparation which has a positive impact on the metabolic processes of plants.

scholarly journals SUHU OPTIMAL UNTUK KELANGSUNGAN HIDUP PEMELIHARAAN LARVA IKAN BOTIA (Chromobotia macrachantus)

2018 ◽  
Vol 3 (2) ◽  
pp. 50
Author(s):  
Muarofah Ghofur ◽  
Muhammad Sugihartono ◽  
Husna Daya Aulia
Keyword(s):  
Water Quality ◽  
Survival Rate ◽  
Extreme Temperature ◽  
Living Organism ◽  
Temperature Treatment ◽  
Quality Parameters ◽  
Treatment Temperature ◽  
Water Quality Parameters ◽  
Optimum Temperature ◽  
High Level

Temperature is one of the most dominant water quality parameters on the survival of fish, and almost every living organism has the optimum temperature for its life. One of the obstacles in the cultivation activity is the high level of death in the most critical phase of the larvae so that the handling and carrying capacity of optimal environmental conditions can minimize the death of the larvae as well as the extreme temperature changes will also cause higher death rates of larvae. In the maintenance effort, the quality and quantity of the resulting larva becomes an important factor, as the success of production support to reach the next phase. Therefore, to find out the larval synthesis is done research about the optimum temperature with treatment temperature 240C, 260C, 280C and 300C to the survival of maintenance of botia larvae (Chromobotia macrachantus). The water quality parameters of CO2, NH3, DO, and pH are carried out at the beginning and end of the study for 28 days. The results showed that the highest survival rate at temperature treatment 240C and 260C with a value of 100%.Keywords : Botia Larvae, Temperature, Survival Rate AbstrakSuhu merupakan salah satu parameter kualitas air yang sangat dominan terhadap kelangsungan hidup ikan, dan hampir setiap organisme yang hidup didalamnya memiliki suhu optimum untuk kehidupannya. Salah satu kendala dalam kegiatan budidaya adalah tingginya tingkat kematian pada fase paling kritis yaitu larva sehingga penanganan dan daya dukung kondisi lingkungan yang optimal dapat meminimalisir kematian larva demikian pula dengan perubahan suhu yang ekstrim juga akan menyebabkan tingkat kematian larva semakin tinggi. Dalam upaya pemeliharaan, kualitas dan kuantitas larva yang dihasilkan menjadi faktor penting, sebagai penunjang keberhasilan produksi  hingga mencapai fase selanjutnya. Oleh karena itu, untuk mengetahui sintasan larva dilakukan penelitian mengenai suhu optimal dengan suhu perlakuan 240C, 260C, 280C dan 300C terhadap kelangsungan hidup pemeliharaan larva ikan botia (Chromobotia macrachantus). Parameter kualitas air yitu CO2, NH3, DO, dan pH dilakukan pada awal dan akhir penelitian yang dilakukan selama 28 hari. Hasil penelitian menunjukkan bahwa tingkat kelangsungan hidup tertinggi pada perlakuan suhu 240C dan 260C dengan nilai sebesar 100%.Kata Kunci : Larva Botia, Suhu,Tingkat Kelangsungan Hidup

scholarly journals The Halophyte Halostachys caspica AP2/ERF Transcription Factor HcTOE3 Positively Regulates Freezing Tolerance in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangliu Yin ◽  
Youling Zeng ◽  
Jieyun Ji ◽  
Pengju Wang ◽  
Yufang Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Abscisic Acid ◽  
Freezing Tolerance ◽  
Critical Role ◽  
Extreme Temperature ◽  
Freezing Stress ◽  
Antioxidant Enzyme Activities ◽  
Transcription Factor Gene ◽  
Factor Gene ◽  
Halostachys Caspica

The APETALA2 (AP2) and ethylene-responsive element-binding factor (ERF) gene family is one of the largest plant-specific transcription factor gene families, which plays a critical role in plant development and evolution, as well as response to various stresses. The TARGET OF EAT3 (TOE3) gene is derived from Halostachys caspica and belongs to the AP2 subfamily with two AP2 DNA-binding domains. Currently, AP2 family mainly plays crucial roles in plant growth and evolution, yet there are few reports about the role of AP2 in abiotic stress tolerance. Here, we report HcTOE3, a new cold-regulated transcription factor gene, which has an important contribution to freezing tolerance. The main results showed that the expression of HcTOE3 in the H. caspica assimilating branches was strongly induced by different abiotic stresses, including high salinity, drought, and extreme temperature (heat, chilling, and freezing), as well as abscisic acid and methyl viologen treatments. Overexpressing HcTOE3 gene (OE) induced transgenic Arabidopsis plant tolerance to freezing stress. Under freezing treatment, the OE lines showed lower content of malondialdehyde and electrolyte leakage and less accumulation of reactive oxygen species compared with the wild type. However, the survival rates, antioxidant enzyme activities, and contents of osmotic adjustment substance proline were enhanced in transgenic plants. Additionally, the OE lines increased freezing tolerance by up-regulating the transcription level of cold responsive genes (CBF1, CBF2, COR15, COR47, KIN1, and RD29A) and abscisic acid signal transduction pathway genes (ABI1, ABI2, ABI5, and RAB18). Our results suggested that HcTOE3 positively regulated freezing stress and has a great potential as a candidate gene to improve plant freezing tolerance.

scholarly journals Freezing Tolerance of Lolium multiflorum/Festuca arundinacea Introgression Forms is Associated with the High Activity of Antioxidant System and Adjustment of Photosynthetic Activity under Cold Acclimation

2020 ◽  
Vol 21 (16) ◽  
pp. 5899 ◽  
Author(s):  
Adam Augustyniak ◽  
Izabela Pawłowicz ◽  
Katarzyna Lechowicz ◽  
Karolina Izbiańska-Jankowska ◽  
Magdalena Arasimowicz-Jelonek ◽  
...  
Keyword(s):  
Gene Expression ◽  
Reactive Oxygen Species ◽  
Cold Acclimation ◽  
Antioxidant System ◽  
Freezing Tolerance ◽  
Photosynthetic Apparatus ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Protein Accumulation ◽  
Oxygen Species

Though winter-hardiness is a complex trait, freezing tolerance was proved to be its main component. Species from temperate regions acquire tolerance to freezing in a process of cold acclimation, which is associated with the exposure of plants to low but non-freezing temperatures. However, mechanisms of cold acclimation in Lolium-Festuca grasses, important for forage production in Europe, have not been fully recognized. Thus, two L. multiflorum/F. arundinacea introgression forms with distinct freezing tolerance were used herein as models in the comprehensive research to dissect these mechanisms in that group of plants. The work was focused on: (i) analysis of cellular membranes’ integrity; (ii) analysis of plant photosynthetic capacity (chlorophyll fluorescence; gas exchange; gene expression, protein accumulation, and activity of selected enzymes of the Calvin cycle); (iii) analysis of plant antioxidant capacity (reactive oxygen species generation; gene expression, protein accumulation, and activity of selected enzymes); and (iv) analysis of Cor14b accumulation, under cold acclimation. The more freezing tolerant introgression form revealed a higher integrity of membranes, an ability to cold acclimate its photosynthetic apparatus and higher water use efficiency after three weeks of cold acclimation, as well as a higher capacity of the antioxidant system and a lower content of reactive oxygen species in low temperature.

scholarly journals Chlorophyll Fluorescence Kinetics May Be Useful to Identify Early Drought and Irrigation Effects on Photosynthetic Apparatus in Field-Grown Wheat

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1275
Author(s):  
Lenka Botyanszka ◽  
Marek Zivcak ◽  
Erik Chovancek ◽  
Oksana Sytar ◽  
Viliam Barek ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Deficit ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Photosynthetic Apparatus ◽  
Optical Methods ◽  
Accurate Information ◽  
Ojip Transient ◽  
Fluorescence Kinetics ◽  
Non Invasive

To assess the reliability and sensitivity of non-invasive optical methods to detect the early effects of water deficit in the field, we analyzed the time-series of non-invasive measurements obtained in a dry season in a representative collection of wheat genotypes grown in small-plot field trials, in non-irrigated and irrigated variants. Despite a progressive water deficit and significant yield loss, the measurements indicated very minor changes in chlorophyll content or canopy cover. This corresponded well to the insignificant differences in spectral reflectance normalized difference vegetation index (NDVI) values. On the other hand, we identified the significant and rapid response of fast fluorescence kinetics data following the onset of irrigation. Analysis of parameters showed the main effects of drought were associated with changes in the amplitude of the I–P phase of the OJIP transient, indicating changes at the level of photosystem I and beyond. Statistical analyses identified the integrative parameter performance index PItot as the most sensitive parameter, which well-reflects the differences in responses of the genotypes to water deficit. Our results suggest that focusing on photosynthetic functions detected by the rapid chlorophyll fluorescence records can provide more accurate information on the drought stress level, compared to the structural data obtained by absorbance or reflectance measurements.

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