scholarly journals Water Content during Abscisic Acid Induced Freezing Tolerance in Bromegrass Cells

1990 ◽  
Vol 93 (2) ◽  
pp. 460-464 ◽  
Author(s):  
Karen Tanino ◽  
Conrad J. Weiser ◽  
Leslie H. Fuchigami ◽  
Tony H. H. Chen
1989 ◽  
Vol 67 (12) ◽  
pp. 3640-3646 ◽  
Author(s):  
Martin J. T. Reaney ◽  
Lawrence V. Gusta ◽  
Suzanne R. Abrams ◽  
Albert J. Robertson

The effects of kinetin and gibberellic acids (GA3, GA4, GA7, GA9, and a mixture of GA4,7,9) on cold hardening, dehardening, and growth of smooth bromegrass (Bromus inermis Leyss. cv. Manchar) suspension cultures treated with abscisic acid (ABA) were determined. Bromegrass cells treated with 75 μM racemic ABA for 7 days at 25 °C tolerated −37 °C, whereas cells treated with both racemic ABA (75 μM) and a mixture of GA4, GA7, and GA9 (total gibberellic acid concentration 100 μM) were similar in hardiness to the controls (LT50, −10 °C). GA4,7,9 at concentrations greater than 10 μM inhibited the growth of cells. Although 400 μM GA4,7,9 was lethal to cells, 75 μM ABA overcame the lethal effect but did not overcome growth inhibition. The twofold reduction in cell water content due to 75 μM ABA treatment for 7 days was partially overcome by GA4,7,9 at concentrations greater than 400 μM. GA4, GA7, and GA9 were equally effective at limiting growth and inhibiting freezing tolerance induced by ABA, whereas GA3 had little effect on cold hardiness, growth, and water content. During the first 4 days, kinetin at concentrations greater than 100 μM inhibited growth of both control cells and cells treated with ABA. Kinetin (> 100 μM) also inhibited freezing tolerance induced by abscisic acid after 4 days, but had no effect after 8 days. Bromegrass cells treated with 75 μM ABA for 7 days were hardened to −37 °C but dehardened to −12 °C after transfer to fresh medium minus ABA after 12 days at 10 °C. GA4,7,9 (40 μM) had no effect on the rate of dehardening, whereas kinetin increased the rate of dehardening.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 280
Author(s):  
Diana Saja-Garbarz ◽  
Agnieszka Ostrowska ◽  
Katarzyna Kaczanowska ◽  
Franciszek Janowiak

The aim of this study was to investigate the accumulation of silicon in oilseed rape and to characterize the changes in chosen water balance parameters in response to drought. The following parameters were estimated: water content, osmotic and water potential, evapotranspiration, stomatal conductance and abscisic acid level under optimal and drought conditions. It was shown that oilseed rape plants accumulate silicon after its supplementation to the soil, both in the case of silicon alone and silicon together with iron. It was revealed that silicon (without iron) helps maintain constant water content under optimal conditions. While no silicon influence on osmotic regulation was observed, a transpiration decrease was detected under optimal conditions after silicon application. Under drought, a reduction in stomatal conductance was observed, but it was similar for all plants. The decrease in leaf water content under drought was accompanied by a significant increase in abscisic acid content in leaves of control plants and those treated with silicon together with iron. To sum up, under certain conditions, silicon is accumulated even in non-accumulator species, such as oilseed rape, and presumably improves water uptake under drought stress.


1999 ◽  
Vol 50 (337) ◽  
pp. 1359-1364 ◽  
Author(s):  
D. J. Carrier ◽  
E. J. Kendall ◽  
C. A. Bock ◽  
J. E. Cunningham ◽  
D. I. Dunstan

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangliu Yin ◽  
Youling Zeng ◽  
Jieyun Ji ◽  
Pengju Wang ◽  
Yufang Zhang ◽  
...  

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.


2020 ◽  
Vol 71 (9) ◽  
pp. 2713-2722 ◽  
Author(s):  
Haicui Xie ◽  
Jianqin Shi ◽  
Fengyu Shi ◽  
Haiyun Xu ◽  
Kanglai He ◽  
...  

Abstract Plants are routinely subjected simultaneously to different abiotic and biotic stresses, such as heat, drought, and insect infestation. Plant–insect interactions in such complex stress situations are poorly understood. We evaluated the performance of the grain aphid (Sitobion avenae) in wheat (Triticum aestivum L.) exposed to a combination of heat and drought stresses. We also performed assays of the relative water content, nutritional quality, and responses of phytohormone signaling pathways. Lower relative water content and accumulation of soluble sugars and amino acids were observed in plants exposed to combined heat and drought stress. These conditions increased abscisic acid levels in the absence of aphids, as well as leading to higher levels of jasmonate-dependent transcripts. The grain aphid infestation further increased abscisic acid levels and the abundance of jasmonic acid- and salicylic acid-dependent defenses under the combined stress conditions. Aphids reared on plants grown under drought stress alone showed lower net reproductive rates, intrinsic rates of increase, and finite rates of increase compared with aphids reared on plants in the absence of stress. The heat-treated plants also showed a decreased aphid net reproductive rate. These findings demonstrate that exposure to a combination of stresses enhances plant defense responses against aphids as well as altering nutritional quality.


1988 ◽  
Vol 87 (2) ◽  
pp. 468-473 ◽  
Author(s):  
Shyam S. Mohapatra ◽  
Ronald J. Poole ◽  
Rajinder S. Dhindsa

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