Nitrate increases ethylene production and aerenchyma formation in roots of lowland rice plants under water stress

2017 ◽  
Vol 44 (4) ◽  
pp. 430 ◽  
Author(s):  
Cuimin Gao ◽  
Lei Ding ◽  
Yingrui Li ◽  
Yupei Chen ◽  
Jingwen Zhu ◽  
...  

Ethylene increases root cortical aerenchyma formation in maize (Zea mays L.), rice (Oryza sativa L.) and other species. To further investigate the effects of nitrate, ammonium and water stress on ethylene production and aerenchyma formation in roots, two lowland rice cultivars (Shanyou 63, hybrid indica, and Yangdao 6, inbred indica) were cultured hydroponically with 10% (w/v) polyethylene glycol to simulate water stress. Water stress decreased shoot biomass, stomatal conductivity and leaf water potential in cultivars fed with nitrate but not with ammonium. Water stress induced more aerenchyma formation in cultivars fed with nitrate rather than ammonium, and increased cortical aerenchyma was found in Yangdao 6. Endogenous ethylene production by roots increased significantly under water stress in plants fed with nitrate rather than ammonium. Exogenous ethylene stimulated root cortical aerenchyma formation. Expression of the ethylene biosynthesis gene 1-aminocyclo-propane-1-carboxylic acid (ACC) synthase (ACS5) was greater in roots fed with nitrate rather than ammonium in the presence and absence of water stress. The expression of ethylene signalling pathway genes involved in programmed cell death (lesion-simulating disease (L.S.D.)1.1 and L.S.D.2; enhanced disease susceptibility (EDS) and phytoalexin-deficient (PAD4)) were regulated by the N form and water stress. In plants of cultivars fed with ammonium, L.S.D.1.1 expression increased under water stress, whereas L.S.D.2, EDS and PAD4 expression decreased. In conclusion, nitrate increases ethylene production and cortical aerenchyma formation in roots of water-stressed lowland rice. However, ammonium increased L.S.D.1.1 expression in water-stressed roots, and decreased ACS5, EDS and PAD4 expression, which would inhibit ethylene production and aerenchyma formation.

2014 ◽  
Vol 1033-1034 ◽  
pp. 677-680
Author(s):  
Ling Li ◽  
Hai Xue Liu ◽  
Yong Bo Peng ◽  
Shi Li ◽  
Tie Ling Liu

The flesh firmness of AC andrinmutant tomato fruits picked freshly were the largest. Respiration rate and ethylene production were very low at this time. With ethylene production increase, fruit firmness began to decline. 100μL/L ethephon significantly increased AC tomato fruit ethylene release, respiration rate, ACS activity and ACO activity, and decreased flesh firmness. However, there were no significant differences inrinmutant between control and ethephon treatment. It was shown RIN transcription factor regulated ethylene biosynthesis by ACC synthase and ACC oxidase.


HortScience ◽  
2014 ◽  
Vol 49 (8) ◽  
pp. 1056-1060 ◽  
Author(s):  
Wei Hu ◽  
Ju-Hua Liu ◽  
Xiao-Ying Yang ◽  
Jian-Bin Zhang ◽  
Cai-Hong Jia ◽  
...  

The banana, a typical climacteric fruit, undergoes a postharvest ripening process followed by a burst in ethylene production that signals the beginning of the climacteric period. Postharvest ripening plays an important role in improving the quality of the fruit as well as limiting its shelf life. To investigate the role of glutamate decarboxylase (GAD) in climacteric ethylene biosynthesis and fruit ripening in postharvest banana, a GAD gene was isolated from banana, designated MuGAD. Coincidently with climacteric ethylene production, MuGAD expression as well as the expression of the genes encoding the Musa 1-aminocyclopropane-1-carboxylate synthase (MaACS1) and Musa 1-aminocyclopropane-1-carboxylate oxidase (MaACO1) greatly increased during natural ripening and in ethylene-treated banana. Moreover, ethylene biosynthesis, ripening progress, and MuGAD, MaACS1, and MaACO1 expression were enhanced by exogenous ethylene application and inhibited by 1-methylcyclopropene (1-MCP). Taken together, our results suggested that MuGAD is involved in the fruit ripening process in postharvest banana.


2020 ◽  
Author(s):  
Yinglin Ji ◽  
Yi Qu ◽  
Zhongyu Jiang ◽  
Xin Su ◽  
Pengtao Yue ◽  
...  

ABSTRACTThe plant hormone ethylene is important for the ripening of climacteric fruit, such as pear (Pyrus ussuriensis), and the brassinosteroid (BR) class of phytohormones affects ethylene biosynthesis during ripening, although via an unknown molecular mechanism. Here, we observed that exogenous BR treatment suppressed ethylene production during pear fruit ripening, and that the expression of the transcription factor PuBZR1 was enhanced by epibrassinolide (EBR) treatment during pear fruit ripening. PuBZR1 was shown to interact with PuACO1, which converts 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene, and suppress its activity. We also observed that BR-activated PuBZR1 bound to the promoters of PuACO1 and of PuACS1a, which encodes ACC synthase, and directly suppressed their transcription. Moreover, PuBZR1 suppressed the expression of transcription factor PuERF2 by binding its promoter, and PuERF2 bound to the promoters of PuACO1 and PuACS1a. We concluded that PuBZR1 indirectly suppresses the transcription of PuACO1 and PuACS1a through its regulation of PuERF2. Ethylene production and the expression profiles of the corresponding apple (Malus domestica) homologs showed similar changes following EBR treatment. Together, these results suggest that BR-activated BZR1 suppresses ACO1 activity and the expression of ACO1 and ACS1a, thereby reducing ethylene production during pear and apple fruit ripening. This likely represents a conserved mechanism by which exogenous BR suppresses ethylene biosynthesis during climacteric fruit ripening.One-sentence summaryBR-activated BZR1 suppresses ACO1 activity and expression of ACO1 and ACS1a, which encode two ethylene biosynthesis enzymes, thereby reducing ethylene production during pear and apple fruit ripening.


1995 ◽  
Author(s):  
William Woodson ◽  
Shimon Mayak ◽  
Haim Rabinowitch

The senescence of carnation (Dianthus caryophyllus L.) flowers is associated with increased production of the phytohormone ethylene, which in turn serves to initiate and regulate the processes involved in programmed petal death. We investigated the regulation of ethylene production and petal senescence in carnation. Several carnation genotypes were identified that exhibited extended vase-life in comparison to flowers from typical commercial cultivars. The capacity of these genotypes to produce ethylene during postharvest vase-life and to respond to exogenous ethylene was investigated. Several genotypes, represented by 'Sandrosa' and 87-37G produced little ethylene durig their postharvest vase-life and as a result failed to exhibit the symptoms (in-rolling and wilting) typical of flowers producing elevated levels of ethylene. These genotypes were further separated by their capacity to respond to exogenous ethylene by both increased ethylene synthesis and premature petal senescence. In one case a genotype (799) was identified that was not capable of responding to exogenous ethylene by either increased ethylene production or premature petal senescence. The regulation of ethylene production during petal senescence was investigated both at the enzyme and gene levels. A full length cDNA was identified for the petal senescence-related ACC synthase gene. Utilizing this, and other ethylene biosynthetic pathway cDNA probes, an increase in both ACC synthase and ACC oxidase mRNAs were detected following ethylene treatment. An increase in ACC oxidase mRNA and enzyme activity was detected within 2-3 h following ethylene treatment, indicating the expression of this gene is an early response to ethylene. An investigation into the expression of novel proteins during petal senescence revealed a number of polypeptides increased in abundance and possibly play a role in the regulation or biochemical processes of senescence. One polypeptide of 70 kDa was identified as being encoded by the previously characterized gene SR12 and possibly represents a b-galactosidase involved in the remobilization of carbohydrates during senescence.


1994 ◽  
Vol 119 (2) ◽  
pp. 282-287 ◽  
Author(s):  
Steven A. Altman ◽  
Theophanes Solomos

Treating `Elliott's White' cut carnations with 50 or 100 mm aminotriazole for 4 days inhibits the respiratory climacteric and significantly extends vase life. Aminotriazole induced time- and concentration-dependent inhibition of ethylene evolution and onset of the ethylene climacteric by inhibiting ACC synthase activity. Flowers treated with 50 or 100 mm aminotriazole for 2 days exhibited concentration-dependent increases in ethylene evolution, respiratory activity, ACC synthase activity, and petal ACC content in response to the application of exogenous ethylene at 10 μl·liter-1. Senescence-associated morphological changes, increased ACC synthase activity, ACC content, and ethylene evolution were completely inhibited in flowers treated for 4 days with 100 mm aminotriazole. Although treatment with 50 mm aminotriazole for 4 days did not completely inhibit components of the ethylene biosynthetic pathway, no morphological or respiratory responses to the application of exogenous ethylene at 10 μl·liter-1 were observed, a result indicating that prolonged aminotriazole treatment inhibited ethylene action. Chemical names used: 3-1H-amino-1,2,4-triazole-1-yl (aminotriazole), 1-aminocyclopropane-1-carboxylic acid (ACC).


2018 ◽  
Vol 115 (21) ◽  
pp. 5606-5611 ◽  
Author(s):  
Qingxin Song ◽  
Atsumi Ando ◽  
Dongqing Xu ◽  
Lei Fang ◽  
Tianzhen Zhang ◽  
...  

Heterosis is widely applied in agriculture; however, the underlying molecular mechanisms for superior performance are not well understood. Ethylene biosynthesis and signaling genes are shown to be down-regulated in Arabidopsis interspecific hybrids. Ethylene is a plant hormone that promotes fruit ripening and maturation but inhibits hypocotyl elongation. Here we report that application of exogenous ethylene could eliminate biomass vigor in Arabidopsis thaliana F1 hybrids, suggesting a negative role of ethylene in heterosis. Ethylene biosynthesis is mediated by the rate-limiting enzyme, 1-aminocyclopropane-1-carboxylate synthase (ACS). Down-regulation of ACS genes led to the decrease of ethylene production, which was associated with the high-vigor F1 hybrids, but not with the low-vigor ones. At the mechanistic level, expression of ACS genes was down-regulated diurnally and indirectly by Circadian Clock Associated 1 (CCA1) during the day and directly by Phyotochrome-Interacting Factor 5 (PIF5) at night. Consistent with the negative role of ethylene in plant growth, biomass vigor was higher in the acs mutants than in wild-type plants, while increasing endogenous ethylene production in the hybridizing parents reduced growth vigor in the hybrids. Thus, integrating circadian rhythms and light signaling into ethylene production is another regulatory module of complex biological networks, leading to biomass heterosis in plants.


2021 ◽  
Author(s):  
Shimon Meir ◽  
Sonia Philosoph-Hadas ◽  
Shoshana Salim ◽  
Adi Segev ◽  
Joseph Riov

ABSTRACTPatharkar and Walker (2016) reported that cauline leaf abscission in Arabidopsis is induced by a cycle of water stress and rewatering, which is regulated by the complex of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA), HAESA (HAE), and HAESA-LIKE2 (HSL2) kinases. However, they stated without presenting experimental results that ethylene is not involved in this process. Since this statement contradicts the well-established role of ethylene in organ abscission induced by a cycle of water stress and rewatering, our present study was aimed to re-evaluate the possible involvement of ethylene in this process. For this purpose, we examined the endogenous ethylene production during water stress and following rewatering, as well as the effects of exogenous ethylene and 1-methylcyclopropene (1-MCP), on cauline leaf abscission of Arabidopsis wild type. Additionally, we examined whether this stress induces cauline leaf abscission in ethylene-insensitive Arabidopsis mutants. The results of the present study demonstrated that ethylene production rates increased significantly in cauline leaves at 4 h after rewatering of stressed plants, and remained high for at least 24 h in plants water-stressed to 40 and 30% of system weight. Ethylene treatment applied to well-watered plants induced cauline leaf abscission, which was inhibited by 1-MCP. Cauline leaf abscission was also inhibited by 1-MCP applied during a cycle of water stress and rewatering. Finally, no abscission occurred in two ethylene-insensitive mutants, ein2-1 and ein2-5, following a cycle of water stress and rewatering. Taken together, these results clearly indicate that ethylene is involved in Arabidopsis cauline leaf abscission induced by water stress.One sentence summaryUnlike Patharker and Walker (2016), our results show that ethylene is involved in Arabidopsis cauline leaf abscission induced by water stress and rewatering, similar to leaf abscission in other plants.


2003 ◽  
Vol 83 (4) ◽  
pp. 817-824 ◽  
Author(s):  
Changwen Lu ◽  
Peter M.A. Toivonen

The effect of a combined treatment comprising a 35% CO2 atmosphere plus 250 nL L-1 1-methylcyclopropene (1-MCP) on shelf life of Gala apples app lied after removal from air or controlled atmosphere (CA) storage was evaluated. Fruit were removed from air storage at 10 and 18 wk and from CA storage at 18 and 22 wk, warmed to 20°C and then treated for 16 h with 1-MCP either in combination with or without 35% CO2. Treated fruit were held at 20°C in air for up to 15 d and assessed every 5 d. Onset of ethylene production was delayed and quality retention was only marginally improved with the 1-MCP treatment. In contrast, both were significantly affected when a 35% CO2 atmosphere was applied in combination with the 1-MCP treatment. Fruit that were treated with 1-MCP in a 35% CO2 atmosphere exhibited the lowest levels of internal ethylene concentration (IEC) and the smallest decline of flesh firmness and titratable acidity (TA) during holding at 20°C. No symptoms of CO2 injury were noted. In the high CO2 atmosphere, a 250 nL L-1 treatment with 1-MCP resulted in similar firmness and titratable acidity retention at room temperature as did a 1000 nL L-1 treatment with 1-MCP. Additionally, the application of the combined 1-MCP/high CO2 treatment after holding at 20°C for 24 h resulted in similar effects as seen if the treatment were applied only 2 h after removal from storage. Biochemical analysis showed that 1-MCP and high CO2 have two distinctly different effects on ACC-synthase activity, explaining the synergistic effect of the combined treatment. Key words: Post-storage ripening, 1-MCP, carbon dioxide, ethylene biosynthesis


1981 ◽  
Vol 8 (6) ◽  
pp. 497 ◽  
Author(s):  
TJ Blake ◽  
DM Reid

Effects of flooding of the roots on ethylene levels and water relations of flood-tolerant and flood-susceptible eucalypts were studied in an attempt to shed light on mechanisms of adaptation to waterlogging. The order of most flood tolerant to least tolerant were Eucalyptus camaldulensis Dehnh., E. globulus Labill., and E. obliqua L'Hérit. Tolerance of flooding in E. camaldulensis was associated with an initial increase in ethylene production by the roots, a subsequent increase in ethylene evolution by the lower stem, and basal stem thickening and aerenchyma formation in response to flooding. In addition, exogenous ethylene gas (500 �ll-1) increased stem thickening in E. camaldulensis seedlings compared with untreated controls. Although treatment of the flood-susceptible E. obliqua with ethylene gas resulted in stem hypertrophy, flooding did not induce either the stem thickening response nor did it stimulate ethylene production. Eucalyptus globulus was intermediate as regards flood tolerance and basal stem thickening; ethylene production by the roots increased but it did not show marked hypertrophy of the unflooded lower stem and was unresponsive to exogenous ethylene gas. Water stress was not associated with flooding damage in eucalypts. Early stomatal closure as shown by high leaf stomatal resistances occurred in both the flood-tolerant and the flood-susceptible species and leaf water potential did not decrease in any of the three species in response to flooding. The results suggest that the high degree of flood-tolerance in E. camaldulensis may be due to (1) increased ethylene production which results in (2) tissue hypertrophy and basal stem thickening. Such tissue hypertrophy would permit the plant to eliminate the build-up of the potentially toxic gas ethylene and could also enhance the transport of oxygen to the roots. The other species lacked one or other of these adaptive mechanisms and exhibited a lesser degree of flood tolerance.


2017 ◽  
Author(s):  
Danner Sagala

Drastically environmental change when submergence occur cause physiologically damages in plant. Submergence inhibits the rate of gas diffusion between plant and atmosphere. The decrease of oxygen interfere the respiration and the inhibition of CO2 into plant disturbs the photosynthesis process. In addition, the plant also experience stress after submergence. There are two types of plant adaptation to submergence, namely tolerance and the elongation ability. The elongation of submerged stem is related to ethylene production. The exogenous ethylene application stimulate the elongation of deepwater rice in aerobic condition . Ethylene biosyntheses is arranged by ACC synthase gene.Versi pre-print


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