A cellulose synthase-like protein is required for osmotic stress tolerance in <i>Arabidopsis</i>

Zhu, Jianhua,Lee, Byeong-Ha,Dellinger, Mike,Cui, Xinping,Zhang, Changqing,Wu, Shang,Nothnagel, Eugene A.,Zhu, Jian-Kang Blackwell Publishing Ltd 2010 The Plant journal Vol.63 No.1

<P>Summary</P><P>Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have previously identified <I>salt overly sensitive</I> (<I>sos</I>) mutants of Arabidopsis that fall into five loci, <I>SOS1</I> to <I>SOS5.</I> These loci are required for the regulation of ion homeostasis or cell expansion under salt stress, but do not play a major role in plant tolerance to the osmotic stress component of soil salinity or drought. Here we report an additional <I>sos</I> mutant, <I>sos6-1,</I> which defines a locus essential for osmotic stress tolerance<I>. sos6-1</I> plants are hypersensitive to salt stress and osmotic stress imposed by mannitol or polyethylene glycol in culture media or by water deficit in the soil. <I>SOS6</I> encodes a cellulose synthase-like protein, AtCSLD5. Only modest differences in cell wall chemical composition could be detected, but we found that <I>sos6-1</I> mutant plants accumulate high levels of reactive oxygen species (ROS) under osmotic stress and are hypersensitive to the oxidative stress reagent methyl viologen. The results suggest that SOS6/AtCSLD5 is not required for normal plant growth and development but has a critical role in osmotic stress tolerance and this function likely involves its regulation of ROS under stress.</P>

Proteomic Analysis of Erythritol-Producing Yarrowia lipolytica from Glycerol in Response to Osmotic Pressure(s)

( Li Bo Yang ),( Xiao Meng Dai ),( Zhi Yong Zheng ),( Li Zhu ),( Xiao Bei Zhan ),( Chi Chung Lin ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.7

Osmotic pressure is a critical factor for erythritol production with osmophilic yeast. Protein expression patterns of an erythritol-producing yeast, Yarrowia lipolytica, were analyzed toidentify differentially-expressed proteins in response to osmotic pressure. In order to analyze intracellular protein levels quantitatively, two-dimensional gel electrophoresis was performed to separate and visualize the differential expression of the intracellular proteins extracted from Y. lipolytica cultured under low (3.17 osmol/kg) and high (4.21 osmol/kg) osmotic pressures. Proteomic analyses allowed identification of 54 differentially-expressed proteins among the proteins distributed in the range of pI 3-10 and 14.4-97.4 kDa molecular mass between the osmotic stress conditions. Remarkably, the main proteins were involved in the pathway of energy, metabolism, cell rescue, and stress response. The expression of such enzymes related to protein and nucleotide biosynthesis was inhibited drastically, reflecting the growth arrest of Y. lipolytica under hyperosmotic stress. The improvement of erythritol production under highosmotic stress was due to the significant induction of a range of crucial enzymes related to polyols biosynthesis, such as transketolase and triosephosphate isomerase, and the osmotic stress responsive proteins like pyridoxine-4-dehydrogenase and the AKRs family. The polyols biosynthesis was really related to an osmotic response and a protection mechanism against hyperosmotic stress in Y. lipolytica. Additionally, the high osmotic stress could also induce other cell stress responses as with heat shock and oxidation stress responses, and these responsive proteins, such as the HSPs family, catalase T, and superoxide dismutase, also had drastically increased expression levels under hyperosmotic pressure.

Differential Osmotic Adjustment to Iso-osmotic NaCl and PEG Stress in the in vitro Cultures of Sesuvium portulacastrum (L.) L.

Vinayak Haribhau Lokhande,Tukaram Dayaram Nikam,Suprasanna Penna 한국작물학회 2010 Journal of crop science and biotechnology Vol.13 No.4

The influence of iso-osmotic (-0.7 MPa) NaCl and PEG stress on growth, osmotic adjustment and antioxidant defense mechanisms was investigated in the in vitro cultures of Sesuvium portulacastrum (L.) L. The decreased relative growth rate (RGR) and water content of PEG-stressed calli in comparison to NaCl was found to be correlated with differences observed in the energy expenditure for the maintenance of osmotic balance. Osmotic adjustment in the NaCl-stressed calli favored higher accumulation of saline ions and soluble sugars, whereas PEG-stressed calli confirmed increased levels of organic osmolytes (proline, glycine betaine and soluble sugars). Permeability of Na+ ions across the membrane revealed increased relative electrolytic leakage (REL) in NaCl-stressed calli,however non-penetrating and highly viscous solution of PEG amplified the peroxidation of membrane lipids. Increased activities of superoxide dismutase and catalase displayed efficient removal of toxic reactive oxygen species in comparison to ascorbate peroxidase in the calli exposed to iso-osmotic stress. These findings suggest that differential tolerance potential to iso-osmotic NaCl and PEG stress in terms of osmotic adjustment appears to be the prime defense mechanism of Sesuvium for its survival under iso-osmotic stress conditions at the expense of reduced growth and water content.

Differential Osmotic Adjustment to Iso-osmotic NaCl and PEG Stress in the in vitro Cultures of Sesuvium portulacastrum (L.) L.

Lokhande, Vinayak Haribhau,Nikam, Tukaram Dayaram,Penna, Suprasanna 한국작물학회 2010 Journal of crop science and biotechnology Vol.13 No.4

The influence of iso-osmotic (-0.7 MPa) NaCl and PEG stress on growth, osmotic adjustment and antioxidant defense mechanisms was investigated in the in vitro cultures of Sesuvium portulacastrum (L.) L. The decreased relative growth rate (RGR) and water content of PEG-stressed calli in comparison to NaCl was found to be correlated with differences observed in the energy expenditure for the maintenance of osmotic balance. Osmotic adjustment in the NaCl-stressed calli favored higher accumulation of saline ions and soluble sugars, whereas PEG-stressed calli confirmed increased levels of organic osmolytes (proline, glycine betaine and soluble sugars). Permeability of $Na^+$ ions across the membrane revealed increased relative electrolytic leakage (REL) in NaCl-stressed calli, however non-penetrating and highly viscous solution of PEG amplified the peroxidation of membrane lipids. Increased activities of superoxide dismutase and catalase displayed efficient removal of toxic reactive oxygen species in comparison to ascorbate peroxidase in the calli exposed to iso-osmotic stress. These findings suggest that differential tolerance potential to iso-osmotic NaCl and PEG stress in terms of osmotic adjustment appears to be the prime defense mechanism of Sesuvium for its survival under iso-osmotic stress conditions at the expense of reduced growth and water content.

A positive transcription factor in osmotic stress tolerance, ZAT10, is regulated by MAP kinases in Arabidopsis

Xuan Canh Nguyen,김선호,Shah Hussain,안종국,유예지,한해주,유주순,임채오,윤대진,정우식 한국식물학회 2016 Journal of Plant Biology Vol.59 No.1

Osmotic stress is induced by several environmental stresses such as drought, cold and salinity. Osmotic stress may finally leads to oxidative damage, ionic imbalance and growth inhibition in plants. Gene expression analyses indicated that ZAT10 transcription factor, a novel substrate of Arabidopsis MPKs, could be induced by environmental stresses that result in osmotic stress. As previously reported, ZAT10 overexpressing transgenic plants showed enhanced tolerance to osmotic stress. However, in contrast to previous report, a zat10 knockout mutant showed an osmotic stress sensitive phenotype. To determine the biological function of EAR domain and phosphorylation sites of ZAT10, we constructed two transgenic plants expressing two ZAT10 mutant proteins having EAR domain mutations (ZAT10EAR) and phosphorylation site mutations (ZAT10AA). The phenotype of zat10 was complemented by the expression of ZAT10EAR mutant, however not by the expression of ZAT10AA mutant, indicating that the phosphorylation sites in ZAT10 by MPKs are involved in stress tolerance but the EAR domain is not. In this report, we suggest that ZAT10 function as a positive regulator in osmotic stress tolerance and the phosphorylation of ZAT10 is required for its function in Arabidopsis.

건조스트레스가 수리취의 광합성 및 수분관련 특성에 미치는 영향

이경철,이학봉,Lee, Kyeong-Cheol,Lee, Hak Bong 한국산림과학회 2017 한국산림과학회지 Vol.106 No.3

이 연구는 건조스트레스가 수리취의 생리적 반응에 미치는 영향을 알아보고자 수행하였으며, 건조스트레스는 25일 간의 단수처리를 통해 유도하였다. 건조스트레스가 진행됨에 따라 새벽 녘 수분포텐셜(${\Psi}_{pd}$)과 정오의 수분포텐셜(${\Psi}_{mid}$)이 모두 감소하였으며, 수분불포화도(WSD)는 약 7배 증가하였다. 특히 일중 수분포텐셜차(${\Psi}_{pd}-{\Psi}_{mid}$)는 처리 후 10일까지 0.22~0.18 MPa 범위로 큰 차이를 나타냈으나 이후에는 차이가 크게 줄어드는 경향을 보였다. 수리취는 건조스트레스 처리 후 15일부터 기공전도도와 기공증산속도의 감소가 두드러졌고, 처리 20일 이후에는 최대광합성 속도와 순양자수율 역시 큰 폭으로 감소한 반면 수분이용효율은 반대의 경향을 보였다. 이것은 기공을 통한 $CO_2$와 수분의 조절이 원활하지 못해 광합성량의 감소가 일어난 것을 의미한다. JIP 분석을 통해 단수처리 15일 이후에 기능지수($PI_{ABS}$) 및 에너지전달 효율의 감소가 두드러진 것으로 나타났으며, 광계 2의 활성이 감소한 것을 보여준다. 엽의 원형질 분리시 삼투포텐셜 ${\Psi}_o{^{tlp}}$은 -0.4 MPa, 최대포수시의 삼투포텐셜 ${\Psi}_o{^{sat}}$은 -0.35 MPa의 삼투적 적응 반응을 나타냈으며, 최대탄성계수($E_{max}$)의 탄성적 적응은 9.4 MPa로 나타나 수리취는 건조스트레스에 따라 삼투적 적응과 탄성적 적응이 모두 나타나는 것을 알 수 있었다. Vo/DW, Vt/DW와 같은 수분특성인자는 건조스트레스에 따라 증가되는 것으로 나타났다. 결과적으로 수리취는 새벽녘 엽수분포텐셜이 -0.93 MPa 이하로 저하되면 광합성 활성의 감소가 크게 나타나고, 건조스트레스에 따라 삼투적 적응과 탄성적 적응이 나타나 이것이 이 식물의 중요한 적응방법임을 알 수 있었다. This study was conducted to find out the influence of drought stress on physiological responses of Synurus deltoides. Drought stress was induced by withholding water for 25 days. Leaf water potentials were decreased of both predawn (${\Psi}_{pd}$) and mid-day (${\Psi}_{mid}$) with increasing drought stress, but water saturation dificit (WSD) was 7 times increased. ${\Psi}_{pd}-{\Psi}_{mid}$ showed the significant difference of 0.22~0.18 MPa in stressed before 10 days, and nonsignificant as treatment time became longer. A strong reduction of stomatal conductance ($gH_2O$) and stomatal transpiration rate (E) were observed after 15 days of drought stress Significant reductions of net apparent quantum yield (${\Phi}$) and maximum photosynthesis rate ($Pn_{max}$) were observed after 20 days of drought stress; However, water use efficiency (WUE) was shown the opposite trend. This implies that decrease of photosynthesis rate may be due to an inability to regulate water and $CO_2$ exchanged through the stomata. From JIP analysis, flux ratios (${\Psi}_O$ and ${\Phi}_{EO}$) and performance index on absorption basis ($PI_{ABS}$) were dramatically decreased withholding water after 15 days, which reflects the relative reduction of photosystem II activity. The leaf of S. deltoides showed osmotic adjustment of -0.35 MPa at full turgor and -0.40 MPa at zero turgor, and also cell-wall elastic adjustment of 9.4 MPa, indicating that S. deltoides tolerate drought stress through osmotic adjustment and cell-wall elastic adjustment. The degree of change in water relations parameters such as Vo/DW, Vt/DW decreased with increasing drought stress. This result showed that S. deltoides was exhibited a strong reduction of photosynthetic activity to approximately -0.93 MPa of predawn leaf water potential, and both of osmotic adjustment and cell-wall elastic adjustment in drought stress condition appears to be an important adaptation for restoration in this species.

Root Development and Anti-Oxidative Response of Rice Genotypes under Polyethylene Glycol Induced Osmotic Stress

Juthy Abedin Nupur,Afsana Hannan,Md. Abir Ul Islam,G H M Sagor,Arif Hasan Khan Robin 한국육종학회 2020 Plant Breeding and Biotechnology Vol.8 No.2

Osmotic stress is a kind of stress which is directly or indirectly related to all other abiotic stresses. Four rice varietiesnamely Binadhan-11 (with SUB1 gene), BRRI dhan52 (with SUB1 gene), Binadhan-7 and BRRI dhan71 were used to study thevariation in root development and anti-oxidative response under osmotic stress conditions. Osmotic stress was induced by applyingpolyethylene glycol (4% PEG) in hydroponic solution. Treatment was given at the panicle initiation stage and leaf samples werecollected at fourteen days after treatment to estimate antioxidant response in terms of ascorbate (APX) and peroxidase (POD) enzymaticactivity. Roots were destructively harvested at 16 days after the stress imposition. The tested varieties showed significant differences inantioxidant responses under the stress condition such as high APX and POD in Binadhan-11 and BRRI dhan52. Significant injury at the4thleaf position (the youngest leaf was the reference) was observed at 8 and 12 days after the treatment. Number of live leaves, shootdry weight, density of second order lateral roots, number of phytomer (Pr) and total roots, number of roots at Pr2, main axis diameterat Pr1, main axis length at Pr1 varied significantly among the varieties × treatment combinations. Binadhan-11 and BRRI dhan52showed comparatively higher osmotic stress tolerance compared to the other two varieties without SUB1 gene, viz., Binadhan-7 andBRRI dhan71. The varieties BRRI dhan52, and Binadhan-11 showed greater capacity to withstand osmotic stress can be further used todevelop stress tolerant variety.

KRAB family is involved in network shifts in response to osmotic stress in camels

Dandan Cao,Shenyuan Wang,Dong Zhang,Yanru Zhang,Junwei Cao,Yongbin Liu,Huanmin Zhou 한국통합생물학회 2022 Animal cells and systems Vol.26 No.6

A feature of the camel is its tolerance to osmotic stress. However, few studies of osmotic stress in vivo or comparative analyses between different tissues of the camel have been performed. Here, we report the roles of Krüppel-associated box domain containing zinc-finger repressor proteins (KRAB-ZFPs) in transcriptional networks under osmotic stress in camels by analyzing transcriptomes of four different tissues under various osmotic conditions. We found that 273 of 278 KRAB-ZFPs were expressed in our data set, being involved in all of the 65 identified networks and exhibiting their extensive functional diversity. We also found that 110 KRAB-ZFPs were hub genes involved in more than half of the networks. We demonstrated that the osmotic stress response is involved in network shifts and that KRAB-ZFPs mediate this process. Finally, we presented the diverse mechanisms of osmotic stress responses in different tissues. These results revealed the genetic architecture of systematic physiological response in vivo to osmotic stress in camels. Our work will lead to new directions for studying the mechanism of osmotic stress response in anti-arid mammals.

Polyethylene Glycol Induced Osmotic Stress Affects Germination and Seedling Establishment of Wheat Genotypes

Shatabdi Ghosh,Md. Abu Shahed,Arif Hasan Khan Robin 한국육종학회 2020 Plant Breeding and Biotechnology Vol.8 No.2

Wheat is globally an important cereal crop. Environmental stress, especially drought stress can play an important rolein the reduction of plant growth, specifically during germination in arid and semi-arid regions. Polyethylene glycol (PEG) treatedhydroponic conditions create negative osmotic potential which is compared with moisture deficit stress. The main objective of thisstudy was to investigate the effects of PEG 6000 induced moderate osmotic stress on germination indices of 22 wheat varieties. In orderto study the effects of osmotic stress on germination indices in wheat cultivars, an experiment was conducted, using a completelyrandomized design with three replications under two different levels of PEG-6000: 0% and 10%. PEG stress significantly reducedpercent germination, shoot length and root length. PEG stress significantly increased root-shoot ratio and oven dry weight. Principalcomponent analysis revealed response of traits of tolerant wheat varieties under osmotic stress. Correlation study revealed thesignificant relationships among germination indices. The variety BARI Gom-30 recorded comparatively higher root length (6 cm),shoot length (7.8 cm), root-shoot ratio (1.37) followed by the variety Sonalika whereas the variety Kalaysona recorded the lowest rootlength (2.7 cm) and shoot length (2.8 cm) under PEG stress. Evolved information of this research including selected traits such asgermination percentage, root-shoot ratio and dry weight of seedlings could be exploited in wheat breeding program for drought andosmotic stress tolerance.

Overexpression of the intertidal seagrass 14-3-3 gene ZjGRF1 enhances the tolerance of transgenic Arabidopsis to salt and osmotic stress

Chen Siting,Qiu Guanglong 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.6

Salinity afects the physiological activities of seagrass by changing the osmotic pressure of seagrass cells, which then afects the structure and function of seagrass community. In this study, we created transgenic Arabidopsis that overexpressed the ZjGRF1 gene from the intertidal seagrass Zostera japonica. We found that transgenic ZjGRF1 Arabidopsis has stronger tolerance to salt stress and osmotic stress than wild type. Under salt stress, the content of reactive oxygen species in transgenic ZjGRF1 Arabidopsis was lower than that in wild-type Arabidopsis. The viability of root cells in transgenic ZjGRF1 Arabidopsis was higher than that of wild type under salt stress. Under salt stress, transgenic ZjGRF1 Arabidopsis accumulated more proline and had higher antioxidant enzyme activities. The rate of water loss rate from overexpressed plants was lower than that of the wild-type plants. The resistance of overexpressed plants to osmotic stress may be enhanced by the ABA-dependent pathway. Our results confrm that ZjGRF1 enhances tolerance to salt and osmotic stress in Z. japonica.