scholarly journals Exogenous Brassinolide Enhances the Growth and Cold Resistance of Maize (Zea mays L.) Seedlings under Chilling Stress

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 488 ◽  
Author(s):  
Yujun Sun ◽  
Yunhan He ◽  
Ali Raza Irfan ◽  
Xinmeng Liu ◽  
Qiaoqiao Yu ◽  
...  

This paper aims to elucidate the effects of exogenous brassinolide (BL) on maize germination and seedling growth under chilling stress. The cold-resistant maize hybrid Tiannong 9 and the cold-sensitive hybrid Tianhe 1 were soaked at the germination stage (6 °C) and leaves were sprayed at seedling stage (4 °C), with BL at concentrations of 0, 0.01, 0.1, and 1 mg/L. The germination rate of the maize seeds and the changes in seedling biomass, antioxidant, photosynthetic, and plant endogenous hormone systems and chloroplast ultrastructures were determined. The results showed that the optimum concentration of BL to alleviate chilling stress in maize seedlings was 0.1 mg/L. This rate effectively increased the germination rate and plant biomass of maize and significantly increased the superoxide dismutase (SOD) peroxidase (POD) and catalase (CAT) activities, the net photosynthetic rate (Pn), stomatal conductance (gs) and transpiration rate (Tr), and seedling auxin (IAA), gibberellin (GA3) and trans zeatin nucleoside (t-ZR) contents under chilling stress. In addition, BL significantly reduced the malondialdehyde (MDA) content, abscisic acid (ABA) content, and intercellular carbon dioxide concentration (Ci). In the comparison of mesophyll cells, the chloroplast membrane of the treatment group was tightly attached to the stroma, and some of the plasma membranes were dissolved, but the overall structure of the chloroplast was relatively complete, and the osmiophilic granules were relatively few. The exogenous application of BL can effectively alleviate the damage caused by a low temperature in maize, maintain the normal characteristics of seedlings in chilling environments, and ensure the development and growth of plant tissue in the later stage.

Horticulturae ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 182
Author(s):  
Junsik Ahn ◽  
Soyeon Oh ◽  
Yang Joo Kang ◽  
KiBum Kim ◽  
Sung-Kwon Moon ◽  
...  

Peanut (Arachis hypogaea L.) seeds were germinated to investigate the effect of the fermentation period of oak tree sawdust on germination viability and seedling characteristics. Its germination rate, seedling weight, length, and total vigor index were assessed. The seeds were sown in oak tree sawdust fermented for 0, 30, 45, and 60 days. The germination rates of the seeds in fermented sawdust were significantly different. The seeds in the 45-day fermented sawdust produced the heaviest biomass weight (4.6 g) with the longest true leaf (1.7 cm) and hypocotyl (3.4 cm) resulting in the highest total vigor index (925.8). In contrast, seeds in 0-day fermented sawdust had the lowest total vigor index (18.3). Microbiome analysis showed that the microbial community in the sawdust changed as the fermentation progressed, indicating that the microbial community seems to affect seed germination physiology. Taken together, 45-day fermented sawdust is recommended for optimal peanut seed germination and seedling growth.


2021 ◽  
Vol 43 ◽  
Author(s):  
Nancy Araceli Godínez-Garrido ◽  
Juan Gabriel Ramírez-Pimentel ◽  
Jorge Covarrubias-Prieto ◽  
Francisco Cervantes-Ortiz ◽  
Artemio Pérez-López ◽  
...  

Abstract: Chitosan is a biopolymer obtained from deacetylation of chitin; it has multiple applications in agriculture as an antifungal, soil conditioner, inducer of defense mechanisms, fruits postharvest coating, leaves and seeds, among others. The objective in this research was to evaluate the effect of chitosan coatings mixed with fungicide (dithiocarbamate) on the germination and germination speed of bean and maize seeds in storage and to determine the retention capacity of the fungicide in the coated seeds under different times of imbibition. Two coating treatments at concentrations of 0.1 and 0.5% chitosan in water, two coatings treatments at 0.1 and 0.5% chitosan supplemented with 0.5% fungicide and a coating without chitosan using only 0.5% fungicide in water were used in bean and maize seed; and as control seeds imbibed in distilled water were used; after treatments, germination percentage and germination speed were determined, also fungicide release were determined at 0, 1, 2 and 6 h of imbibition, and the effect of storage time on germination and germination speed was determined at 30, 60, 90, 120, 150 and 180 days of storage at 4 °C and 45% relative humidity. The fungicide release effect was determined by inhibiting Fusarium oxysporum conidia germination. There were no negative effects of coatings on seed germination after storage. The treatment that provided both greater retention of the fungicidal agent and released it gradually, was 0.5% chitosan mixed with fungicide concentration. Chitosan coating seeds mixed with fungicide do not cause negative changes in seed germination or germination rate.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Lijuan Yang ◽  
Daibin Yang ◽  
Xiaojing Yan ◽  
Li Cui ◽  
Zhenying Wang ◽  
...  
Keyword(s):  

1988 ◽  
Vol 66 (7) ◽  
pp. 1381-1390 ◽  
Author(s):  
J. Escarré ◽  
C. Houssard

Germination of Rumex acetosella L. was studied under a variety of experimental conditions to determine whether populations from old fields of different ages (fallow for 6 months to 15 years) differed in seed weight and germination rate and in plant biomass and flowering rate of the resulting plants. Fresh seeds collected from these natural populations showed differences in germination that varied with the date of harvest and the number of years since the field was last cultivated: seeds of the youngest population harvested in July germinated the best and were lighter than those of the other populations. Different fertilizer levels applied during the growth of the mother plants from seeds collected in the original old fields affected the mean weight and the germination rate of the resulting seeds, regardless of the density of cultivation of the mother plant. However, the effect of different fertilizer levels on mean seed weight varied with the origin of each population. Heavy seeds (mean weight > 0.6 mg) of mother plants from the populations of fields abandoned over 2 years ago germinated better than light seeds (mean weight < 0.6 mg). There was no significant difference between heavy and light seeds in terms of percent germination for seeds from mother plants that came from the "youngest" field. These differences in germination rate observed in field-collected seeds were also found in light seeds of the offspring generation: light seeds of the mother plant from the population belonging to the more recently abandoned old field germinated the best. Plants grown from heavy seeds that came from the other populations of older fields had more biomass than those resulting from light seeds. This difference has not been observed between individuals resulting from light and heavy seeds of the youngest population. On the other hand, these individuals had a higher flowering rate than those resulting from the older populations. These results are interpreted in relation to the successional status of the populations: high flowering and early germination rates are suitable characteristics for establishment of plants on bare ground or after a disturbance, whereas heavy seeds with more reserves ensure germination and enough biomass of the resulting plants in density-dependent conditions.


Author(s):  
Mohammed Abdul Rahman Al-Muwayhi

In our previous study, we observed that paracetamol (panadol) influences the germination rate and growth biomarker of the Vigna radiate plants. To dissect out the paracetamol mediated changes in this study was undertaken. For this study, 10 days old seedling of Vigna radiata exposed to range of pandol concentration (.005, .01, .1, or 1.0 mg/L) through foliage of plants and harvested at 31st day. Obtained data revealed the dual response of panadol concentration: 0.1 mg/L of panadol significantly increased chlorophyll and leaf gas exchange traits (net photosynthetic rate, stomatal conductance, internal carbon dioxide concentration, water use efficiency and maximum quantum yield of PS II), whereas, 1.0 mg/L of panadol significantly reduced the above parameters. It is therefore concluded that low level of panadol enhanced photosynthetic efficiency of Vigna radiata plants; however, the response is concentration dependent and could be used as growth regulators for Vigna radiata plants.


Botany ◽  
2012 ◽  
Vol 90 (9) ◽  
pp. 845-855 ◽  
Author(s):  
Yang Wang ◽  
Jin Hu ◽  
Guochen Qin ◽  
Huawei Cui ◽  
Qitian Wang

One kind of biologically active salicylic acid (SA) analogue (acetylsalicylic acid, ASA) and two inactive compounds (4-aminosalicylic acid and 4-aminobenzoic acid), along with SA were chosen to evaluate their role in inducing chilling tolerance of two different chilling-tolerant maize ( Zea mays L.) inbred lines. These compounds were applied as seed treatments or as a hydroponic application. The results showed that four compounds had no significant effect on germination of maize seeds; however, SA or ASA soaking treatments significantly increased the root length, shoot height, and shoot and root dry weights of seedlings grown under chilling stress. Hydroponic applications of SA or ASA significantly alleviated the accumulation of malondialdehyde, hydrogen peroxide, and superoxide radicals in roots and leaves of both lines under chilling stress, and the applications also increased the photosynthetic pigments, including chlorophyll a, chlorophyll b, and carotenoids. However, 4-aminosalicylic acid and 4-aminobenzoic acid applications had no significant effect in ameliorating the growth inhibition of seedlings under chilling stress. This study showed that SA and ASA significantly induced the chilling tolerance of maize; however, 4-aminosalicylic acid and 4-aminobenzoic acid were not effective in inducing tolerance to chilling stress. The results suggest that only SA analogues with biological activity may have the ability to induce chilling tolerance of maize.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wajeeha Munawar ◽  
Amjad Hameed ◽  
Muhammad Khashif Riaz Khan

Cotton is a primary agriculture product important for fiber use in textiles and the second major oil seed crop. Cotton is considered as moderately tolerant to salt stress with salinity threshold of 7.7 dS/m at seedling stage. Salinity causes reduction in the growth of seedlings and cotton production that limits fiber quality and cotton yield. In this study, initially, 22 cotton genotypes were screened for relative salt tolerance using germination test in Petri plates (growth chamber). Selected 11 genotypes were further tested in pot experiment (sand) with 0, 15, and 20 dS/m NaCl treatments under glass house conditions. At four-leaves stage, different morphological and physiological traits were measured for all genotypes while biochemical analysis was performed on selected seven highly tolerant and sensitive genotypes. NaCl treatment significantly reduced plant biomass in two genotypes IR-NIBGE-13 and BS-2018, while NIAB-135, NIAB-512, and GH-HADI had least difference in fresh weight between the control and NaCl-treated plants. Photosynthetic rate was maintained in all the genotypes with the exception of SITARA-16. In two sensitive genotypes (IR-NIBGE-13 and 6071/16), Na+ ion accumulated more in leaves as compared to K+ ion under stress conditions, and an increase in Na+/K+ ratio was also observed. The lesser accumulation of malondialdehyde (MDA) content and higher activity of enzymatic antioxidants such as superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) in stressed plants of NIAB-135, NIAB-512, and FH-152 indicated that these genotypes had adaption capacity for salinity stress in comparison with sensitive genotypes, i.e., IR-NIBGE-13 and 6071/16. The observed salt tolerance was corelated with plant biomass maintenance (morphological), photosynthetic rate, and ionic homeostasis (K+/Na+ ratio, physiological) and biochemical stress marker regulations. After a series of experiments, it was concluded that NIAB-135, NIAB-512, and FH-152 could be utilized in breeding programs aimed at improving salinity tolerance in cotton and can expand cotton cultivation in saline area.


2021 ◽  
Vol 26 (52) ◽  
pp. 145-150
Author(s):  
Zlatica Mamlić ◽  
Ivana Maksimović ◽  
Jovan Crnobarac ◽  
Vuk Đorđević ◽  
Marina Delić-Putnik ◽  
...  

Priming of legume seeds before sowing was performed by Roman farmers in order to increase the germination rate and synchronize germination, as reported by the Roman naturalist Gaius Plinius Secundus. Several centuries later, this technique is still used for a wide range of species. However, in order for this measure to be used successfully in production, it is necessary to find a solution for the successful storage of primed seeds. The storage potential of primed soybean seeds was determined by a temperature of 25 °C during the period of 90 days. Soybean seeds were primed with KNO3 (1%), AsA (100 mg L-1) and KCl (1%) solutions, and then stored in natron paper bags, and their quality was tested every 15 days. The results showed that a reduction in the quality of primed seeds was considerably faster than in non-primed seeds. Primed soybean seeds were successfully stored at a temperature of 25 °C for 60 days after priming, and then a significant reduction in their quality occurred. One of the causes of seed quality reduction was an increase in MDA content, especially after 75 and 90 days of storage. Also, free proline concentration was reduced while the content of vitamin C increased after 15 days primarily in seeds primed in AsA and KCl solutions, and decreased after 45 days.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xin Fu ◽  
Yi-Qing Feng ◽  
Xiao-Wei Zhang ◽  
Yan-Yan Zhang ◽  
Huan-Gai Bi ◽  
...  

Salicylic acid (SA) has been proven to be a multifunctional signaling molecule that participates in the response of plants to abiotic stresses. In this study, we used cold-sensitive cucumber and cold-tolerant pumpkin as experimental materials to examine the roles of SA in root–shoot communication responses to aerial or/and root-zone chilling stress in own-root and hetero-root grafted cucumber and pumpkin plants. The results showed that pumpkin (Cm) rootstock enhanced the chilling tolerance of grafted cucumber, as evidenced by the observed lower levels of electrolyte leakage (EL), malondialdehyde (MDA), and higher photosynthetic rate (Pn) and gene expression of Rubisco activase (RCA). However, cucumber (Cs) rootstock decreased the chilling tolerance of grafted pumpkins. Cs/Cm plants showed an increase in the mRNA expression of C-repeat-binding factor (CBF1), an inducer of CBF expression (ICE1), and cold-responsive (COR47) genes and CBF1 protein levels in leaves under 5/25 and 5/5°C stresses, or in roots under 25/5 and 5/5°C stresses, respectively, compared with the Cs/Cs. Chilling stress increased the endogenous SA content and the activity of phenylalanine ammonia-lyase (PAL), and the increase in SA content and activity of PAL in Cs/Cm plants was much higher than in Cs/Cs plants. Transcription profiling analysis revealed the key genes of SA biosynthesis, PAL, ICS, and SABP2 were upregulated, while SAMT, the key gene of SA degradation, was downregulated in Cs/Cm leaves, compared with Cs/Cs leaves under chilling stress. The accumulation of SA in the Cs/Cm leaves was mainly attributed to an increase in SA biosynthesis in leaves and that in transport from roots under aerial and root-zone chilling stress, respectively. In addition, exogenous SA significantly upregulated the expression level of cold-responsive (COR) genes, enhanced actual photochemical efficiency (ΦPSII), maximum photochemical efficiency (Fv/Fm), and Pn, while decreased EL, MDA, and CI in grafted cucumber. These results suggest that SA is involved in rootstock–scion communication and grafting-induced chilling tolerance by upregulating the expression of COR genes in cucumber plants under chilling stress.


2021 ◽  
Author(s):  
Shahab Hatamipoor ◽  
Leila Shabani ◽  
Sadegh Farhadian

Abstract Background The exogenous application of priming molecules to plants helps them to develop tolerance against salinity stress. In the present study, we used exogenous naringenin (0.5 mM) pretreatment before the stress in safflower seedlings under 25 mM NaCl to elucidate the role of naringenin to alleviate oxidative conditions associated with salinity complications. Results Our results showed biomass, leaf relative water content, chlorophyll content, K+ content, and K+/Na+ ratio were negatively affected by 25 mM NaCl. However, the H2O2 accumulation, malondialdehyde (MDA) content, antioxidant enzymes and Na+ content of NaCl-stressed safflower seedlings were remarkably increased. The results obtained in the present study showed the beneficial effects of the pre-treatment of naringenin in safflower seedlings under non-salinity stress condition with respect to increasing plant biomass, total phenolic compound, radical scavenging activity (RSA), soluble sugar content, proline, glutathione, enzymatic antioxidants, and K+ content. Also, the results showed that naringenin pre-treatment can (partly) be overcome NaCl-induced stress on safflower seedlings, probably due to higher accumulation of plant biomass, total phenolic compound, RSA, catalase (CAT) activity, and K+/Na+ ratio as well as lowering the H2O2 and MDA content in the leaves. Conclusions Generally, it could be concluded that, pre-treatment of naringenin before stress could partly diminish NaCl-caused oxidative stress in safflower seedlings, probably due to improvement in enzymatic and non-enzymatic antioxidant and reduced cell membrane damage.


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