ABA-dependent sucrose regulation of antioxidant metabolism in wheat cultivars varying in ABA-sensitivity

Biologia ◽  
2015 ◽  
Vol 70 (2) ◽  
Author(s):  
Sandeep Kaur ◽  
Anil Kumar Gupta ◽  
Vikramjit Kaur Zhawar

AbstractEffect of sucrose and its abscisic acid (ABA) dependence was studied for seed germination, growth and antioxidant related parameters in two wheat cultivars PBW343 (ABA-lesser sensitive) and C306 (ABA-higher sensitive) by using sucrose (Suc) with or without sodium tungstate (inhibitor for ABA biosynthesis) in culture medium. Exogenous Suc (at 1.5% and 3%) inhibited germination in both cultivars where ABA-dependency for such inhibitions was seen only under 3% sucrose in PBW343 and 1.5% sucrose in C306. Exogenous Suc at 1.5% stimulated growth, which was ABA-dependent in both cultivars. Exogenous Suc at 3% inhibited growth in both cultivars but such inhibitions were ABA-dependent only in PBW343. Suc supply (3%) decreased antioxidant enzymes and H

1999 ◽  
Vol 9 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Nurit Roth-Bejerano ◽  
Norbert J.A. Sedee ◽  
Rene M. van der Meulen ◽  
Mei Wang

AbstractThe role of abscisic acid (ABA) in seed germination of two cultivars of lettuce (Lactuca sativa L.; light-sensitive Ritsa and light-insensitive Strada) was investigated. The inhibition of Ritsa seed germination by exogenous ABA was higher than that of Strada seeds, the extent of inhibition of both cultivars being reduced by a short light break. At 25°C the sensitivity of both cultivars to exogenous ABA was higher than at 15°C. The endogenous level of ABA was similar in dry seeds of both cultivars, increasing temporarily in Ritsa seeds during the first 4 h of imbibition in darkness but not in Strada seeds, nor in Ritsa seeds exposed to a short light break. The transitory increase of ABA content in Ritsa seeds imbibed in darkness was accompanied by increased expression of the gene responsive to ABA (Rab) under these conditions. Zorial (Norflurazone), an ABA-biosynthesis inhibitor, decreased ABA content and allowed dark germination of the light-requiring Ritsa seeds. A short light break induced germination of Ritsa seeds when applied at 24 and 48 h after imbibition onset, i.e. after the transitory increase of ABA. GA3, on the other hand was effective when applied at the beginning of imbibition. It seems that light induces germination of the photoblastic Ritsa seeds by both inhibiting ABA synthesis and decreasing seed sensitivity to ABA and inhibitory processes induced by it.


2021 ◽  
Vol 22 (12) ◽  
pp. 6557
Author(s):  
Li-Ying Ren ◽  
Heng Zhao ◽  
Xiao-Ling Liu ◽  
Tong-Kai Zong ◽  
Min Qiao ◽  
...  

Gastrodia elata is a well-known medicinal and heterotrophic orchid. Its germination, limited by the impermeability of seed coat lignin and inhibition by abscisic acid (ABA), is triggered by symbiosis with fungi such as Mycena spp. However, the molecular mechanisms of lignin degradation by Mycena and ABA biosynthesis and signaling in G. elata remain unclear. In order to gain insights into these two processes, this study analyzed the transcriptomes of these organisms during their dynamic symbiosis. Among the 25 lignin-modifying enzyme genes in Mycena, two ligninolytic class II peroxidases and two laccases were significantly upregulated, most likely enabling Mycena hyphae to break through the lignin seed coats of G. elata. Genes related to reduced virulence and loss of pathogenicity in Mycena accounted for more than half of annotated genes, presumably contributing to symbiosis. After coculture, upregulated genes outnumbered downregulated genes in G. elata seeds, suggesting slightly increased biological activity, while Mycena hyphae had fewer upregulated than downregulated genes, indicating decreased biological activity. ABA biosynthesis in G. elata was reduced by the downregulated expression of 9-cis-epoxycarotenoid dioxygenase (NCED-2), and ABA signaling was blocked by the downregulated expression of a receptor protein (PYL12-like). This is the first report to describe the role of NCED-2 and PYL12-like in breaking G. elata seed dormancy by reducing the synthesis and blocking the signaling of the germination inhibitor ABA. This study provides a theoretical basis for screening germination fungi to identify effective symbionts and for reducing ABA inhibition of G. elata seed germination.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1394
Author(s):  
Agnieszka Kuźniar ◽  
Kinga Włodarczyk ◽  
Ilona Sadok ◽  
Magdalena Staniszewska ◽  
Małgorzata Woźniak ◽  
...  

Liquid chromatography–tandem mass spectrometry (LC–MS/MS), colorimetry, and bioassays were employed for the evaluation of the ability of endophytic bacterial strains to synthesize indole-related compounds (IRCs) and in particular indole-3-acetic acid (IAA). A total of 54 endophytic strains belonging to seven bacterial genera isolated from tissues of common and spelt wheat cultivars were studied. The endophytic bacteria isolated from different tissues of the tested wheat types were capable of IRCs production, including IAA, which constituted from 1.75% to 52.68% of all IRCs, in in vitro conditions via the tryptophan dependent pathway. The selected post-culture medium was also examined using a plant bioassay. Substantial growth of wheat coleoptile segments treated with the bacterial post-culture medium was observed in several cases. Our data suggest that the studied endophytic bacteria produce auxin-type compounds to support plant development. Summarizing, our approach to use three complementary methods for estimation of IRCs in different endophytic strains provides a comprehensive picture of their effect on wheat growth.


Planta ◽  
2004 ◽  
Vol 220 (2) ◽  
pp. 251-261 ◽  
Author(s):  
E. A. Amaral da Silva ◽  
Peter E. Toorop ◽  
Adriaan C. van Aelst ◽  
Henk W. M. Hilhorst

2021 ◽  
Author(s):  
Mingming Yang ◽  
Linda S Thomashow ◽  
David M Weller

Pseudomonas brassicacearum Q8r1-96 and other 2,4-diacetylphloroglucinol (DAPG)-producing pseudomonads of the Pseudomonas fluorescens complex possess both biocontrol and growth-promoting properties and play an important role in suppression of take-all of wheat in the Pacific Northwest (PNW) of the United States. However, P. brassicacearum can also reduce seed germination and cause root necrosis on some wheat cultivars. We evaluated the effect of Q8r1-96 and DAPG on the germination of 69 wheat cultivars that have been or currently are grown in the PNW. Cultivars varied widely in their ability to tolerate P. brassicacearum or DAPG. The frequency of germination of the cultivars ranged from 0 to 0.87 and from 0.47 to 0.90 when treated with Q8r1-96 and DAPG, respectively. There was a significant positive correlation between the frequency of germination of cultivars treated with Q8r1-96 in assays conducted in vitro and in the greenhouse. The correlation was greater for spring than for winter cultivars. In contrast, the effect of Q8r1-96 on seed germination was not correlated with that of DAPG alone, suggesting that DAPG is not the only factor responsible for the phytotoxicity of Q8r1-96. Three wheat cultivars with the greatest tolerance and three cultivars with the least tolerance to Q8r1-96 were tested for their ability to support root colonization by strain Q8r1-96. Cultivars with the greatest tolerance supported significantly greater populations of strain Q8r1-96 than those with the least tolerance to the bacteria. Our results show that wheat cultivars differ widely in their interaction with P. brassicacearum and the biocontrol antibiotic DAPG.


2021 ◽  
Author(s):  
Aiju Meng ◽  
Daxing Wen ◽  
Chunqing Zhang

Spring maize is usually subjected to low-temperature stress during seed germination, which retards seedling growth even if under a suitable temperature. However, the mechanism underlying maize seed germination under low-temperature stress modulating seedling growth after being transferred to normal temperature is still ambiguous. In this study, we used two maize inbred lines with different low-temperature resistance (SM and RM) to investigate the mechanism. The results showed that the SM line had higher lipid peroxidation and lower total antioxidant capacity and germination percentage than the RM line under low-temperature stress, which indicated that the SM line was more vulnerable to low-temperature stress. Further transcriptome analysis revealed that seed germination under low-temperature stress caused down-regulation of photosynthesis related gene ontology (GO) terms in two lines. Moreover, the SM line displayed down-regulation of ribosome and superoxide dismutase (SOD) related genes, whereas genes involved in SOD and vitamin B6 were up-regulated in the RM line. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that photosynthesis and antioxidant metabolism related pathways played important roles in seed germination in response to low-temperature stress, and the photosynthetic system displayed a higher damage degree in the SM line. Both qRT-PCR and physiological characteristics experiments showed similar results with transcriptome data. Taken together, we propose a model for maize seed germination in response to low-temperature stress.


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