Ectopic Expression of a Salt-Inducible Gene, LcSAIN3, from Sheepgrass Improves Seed Germination and Seedling Growth under Salt Stress in Arabidopsis

Sheepgrass is a perennial native grass species in China, and it can tolerate high levels of salt stress with an aggressive and vigorous rhizome system. Many salt-stress-responsive genes have been identified in sheepgrass. In this study, we report the cloning and characterization of a novel salt-induced gene, LcSAIN3 (Leymus chinensis salt-induced 3), from sheepgrass. Expression analysis confirmed that LcSAIN3 was induced by PEG, ABA, and salt treatments, and the expression of LcSAIN3 was significantly increased in salt-tolerant germplasms under salt treatment. Subcellular localization analysis indicated that the GFP-LcSAIN3 protein was mainly localized in the chloroplasts. The heterologous expression of LcSAIN3 in Arabidopsis increased the seed germination rate of transgenic plants under salt, ABA, and mannitol treatments. The seedling survival rate, plant height, and fresh weight of the transgenic plants were higher than those of WT plants under salt stress. The overexpression of LcSAIN3 caused a relatively high accumulation of free proline, enhanced SOD activity, and led to the upregulation of several stress-responsive genes such as AtRD26, AtRD29B, AtSOS1, and AtP5CS1. These results suggest that LcSAIN3 could be a potential target for molecular breeding to improve plants’ salt tolerance.

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Lcsain3, A Novel Gene From Sheepgrass, Regulates Arabidopsis Seed Germination And Seedling Growth Under Salt Stress

10.21203/rs.3.rs-169077/v1 ◽

2021 ◽

Author(s):

Xiaoxia Li ◽

Weiguang Yang ◽

Qian Li ◽

Pincang Zhao ◽

Junting Jia ◽

...

Keyword(s):

Salt Stress ◽

Seed Germination ◽

Molecular Breeding ◽

Seedling Survival ◽

Grass Species ◽

Sod Activity ◽

High Accumulation ◽

Localization Analysis ◽

Stress Responsive Genes ◽

Rhizome System

Abstract Sheepgrass is a perennial native grass species with an aggressive and vigorous rhizome system, and it can tolerate high levels of salt stress. Many salt stress-responsive genes have been identified in sheepgrass. Here, we identified and characterized a novel salt-induced gene, LcSAIN3 (Leymus chinensis salt-induced 3), from sheepgrass. Expression analysis confirmed that LcSAIN3 is induced by PEG, ABA and salt stress. Subcellular localization analysis indicated that the LcSAIN3 protein is mainly localized in the chloroplasts. The heterologous of LcSAIN3 in Arabidopsis increases seed germination under various stress conditions. More importantly, the seedling survival, plant height and weight of the transgenic plants are higher than those of the WT plants under salt stress. The overexpression of LcSAIN3 causes a relatively high accumulation of free proline; enhances SOD activity; and leads to the upregulated expression of several stress-responsive genes, such as AtRAB26, AtRD29B, AtSOS1 and AtP5CS1. Our results suggest that LcSAIN3 may be a useful gene for the molecular breeding to improve plants salt stress tolerance.

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The efficacy of different seed priming agents for promoting sorghum germination under salt stress

PLoS ONE ◽

10.1371/journal.pone.0245505 ◽

2021 ◽

Vol 16 (1) ◽

pp. e0245505

Author(s):

Xiaofei Chen ◽

Ruidong Zhang ◽

Yifan Xing ◽

Bing Jiang ◽

Bang Li ◽

...

Keyword(s):

Salt Stress ◽

Seed Germination ◽

Germination Rate ◽

Principal Component ◽

Dry Weight ◽

Seed Priming ◽

Nacl Stress ◽

Future Research ◽

Fresh Weight ◽

Positive Effects

Sorghum [Sorghum bicolor (L.) Moench] seed germination is sensitive to salinity, and seed priming is an effective method for alleviating the negative effects of salt stress on seed germination. However, few studies have compared the effects of different priming agents on sorghum germination under salt stress. In this study, we quantified the effects of priming with distilled water (HP), sodium chloride (NaCl), potassium chloride (KCl), calcium chloride (CaCl2), and polyethylene glycol (PEG) on sorghum seed germination under 150 mM NaCl stress. The germination potential, germination rate, germination index, vigor index, root length, shoot length, root fresh weight, shoot fresh weight, root dry weight, and shoot dry weight were significantly reduced by salt stress. Different priming treatments alleviated the germination inhibition caused by salt stress to varying degrees, and 50 mM CaCl2 was the most effective treatment. In addition, the mitigation effect of priming was stronger on root traits than on shoot traits. Mitigation efficacy was closely related to both the type of agent and the concentration of the solution. Principal component analysis showed that all concentrations of CaCl2 had higher scores and were clearly distinguished from other treatments based on their positive effects on all germination traits. The effects of the other agents varied with concentration. The priming treatments were divided into three categories based on their priming efficacy, and the 50, 100, and 150 mM CaCl2 treatments were placed in the first category. The 150 mM KCl, 10% PEG, HP, 150 mM NaCl, 30% PEG, and 50 mM KCl treatments were placed in the second category, and the 100 mM NaCl, 100 mM KCl, 20% PEG, and 50 mM NaCl treatments were least effective and were placed in the third category. Choosing appropriate priming agents and methods for future research and applications can ensure that crop seeds germinate healthily under saline conditions.

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Inducing salt tolerance in sweet corn by magnetic priming

Acta agriculturae Slovenica ◽

10.14720/aas.2017.109.1.09 ◽

2017 ◽

Vol 109 (1) ◽

pp. 89 ◽

Cited By ~ 13

Author(s):

Soheil Karimi ◽

Saeid ESHGHI ◽

Saeid KARIMI ◽

Saman HASAN-NEZHADIAN

Keyword(s):

Salt Stress ◽

Seed Germination ◽

Plant Growth ◽

Sweet Corn ◽

Germination Rate ◽

Nacl Stress ◽

Proline Accumulation ◽

Membrane Thermostability ◽

Germination And Growth ◽

Magnetic Priming

This study evaluates seed germination and growth of sweet corn under NaCl stress (0, 50, and 100 mM), after exposing the seeds to weak (15 mT) or strong (150 mT) magnetic fields (MF) for different durations (0, 6, 12, and 24 hours). Salinity reduced seed germination and plant growth. MF treatments enhanced rate and percentage of germination and improved plant growth, regardless of salinity. Higher germination rate was obtained by the stronger MF, however, the seedling were more vigorous after priming with 15 mT MF. Proline accumulation was observed in parallel with the loss of plant water content under 100 mM NaCl stress. MF prevented proline accumulation by improving water absorption. Positive correlation between H2O2 accumulation and membrane thermostability (MTI) was found after MF treatments, which revealed that MF primed the plant for salinity by H2O2 signaling. However, over-accumulation of H2O2 after prolonged MF exposure adversely affected MTI under severe salt stress. In conclusion, magnetic priming for 6 hours was suggested for enhancing germination and growth of sweet corn under salt stress.

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Comparative studies on salt tolerance of seedlings for one cultivar of puccinellia (Puccinellia ciliata) and two cultivars of tall wheatgrass (Thinopyrum ponticum)

Australian Journal of Experimental Agriculture ◽

10.1071/ea03156 ◽

2005 ◽

Vol 45 (4) ◽

pp. 391 ◽

Cited By ~ 8

Author(s):

B. Zhang ◽

B. C. Jacobs ◽

M. O'Donnell ◽

J. Guo

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Seed Germination ◽

Germination Rate ◽

Seedling Emergence ◽

Salt Tolerant ◽

Mineral Contents ◽

Shoot Height ◽

Thinopyrum Ponticum ◽

Tall Wheatgrass

Salt tolerances of 3 cultivars, Menemen puccinellia (Puccinellia ciliata Bor), Tyrrell and Dundas [tall wheatgrass, Thinopyrum ponticum (Podp.) Z. W. Liu and R. R. C. Wang], were compared with respect to their seed germination, adaptive responses to salt and waterlogging, seedling emergence, plant growth, shoot osmolality and mineral contents in a series of salt-stress experiments. An inverse normal distribution provided good fits for the time to seed germination. Under NaCl stress, 50% of the control (distilled water) seed germination rates of Menemen, Tyrrell and Dundas were achieved in 178.8, 300.9 and 296.8 mmol/L NaCl, respectively. Fifty percent of the control seedling emergence rates of these 3 cultivars were in 92.7, 107.2 and 113.5 mmol/L NaCl, respectively. The seed germination rates of these 3 cultivars under both salt and waterlogging stress were far lower than those germinated only under salt stress at the same salt level. Seed pretreatment by soaking seed in NaCl solutions greatly increased the seed germination rate under salt stress for Menemen and under both salt stress and waterlogging for Dundas. Tyrrell and Dundas were very similar in their tolerance to salt stress, and were significantly (P<0.05) more salt tolerant than Menemen in terms of seed germination and seedling emergence rate. Both shoot height and dry matter of these 3 cultivars were not statistically different among all salt stress levels during the seedling elongation period, indicating that the established plants of these 3 cultivars were very salt tolerant. The salt tolerance mechanisms of these 3 cultivars are possibly related to their abilities to maintain high osmolality in shoots by regulating high sodium and potassium contents, and reducing calcium deficiency under salt stress.

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Seed encrusting with salicylic acid: A novel approach to improve establishment of grass species in ecological restoration

PLoS ONE ◽

10.1371/journal.pone.0242035 ◽

2021 ◽

Vol 16 (6) ◽

pp. e0242035

Author(s):

Simone Pedrini ◽

Jason C. Stevens ◽

Kingsley W. Dixon

Keyword(s):

Salicylic Acid ◽

Seed Germination ◽

Ecological Restoration ◽

Seedling Survival ◽

Seedling Emergence ◽

Field Conditions ◽

Grass Species ◽

Seed Coating ◽

Seedling Density ◽

Survival And Growth

To achieve global ambitions in large scale ecological restoration, there is a need for approaches that improve the efficiency of seed-based interventions, particularly in overcoming the bottleneck in the transition from germination to seedling establishment. In this study, we tested a novel seed-based application of the plant stress modulator compound salicylic acid as a means to reduce seedling losses in the seed-to-seedling phase. Seed coating technology (encrusting) was developed as a precursor for optimising field sowing for three grass species commonly used in restoration programs, Austrostipa scabra, Microlaena stipoides, and Rytidosperma geniculatum. Salicylic acid (SA, 0.1mM) was delivered to seeds via imbibition and seed encrusting. The effects of SA on seed germination were examined under controlled water-limited conditions (drought resilience) in laboratory setting and on seed germination, seedling emergence, seedling growth and plant survival in field conditions. Salicylic acid did not impact germination under water stress in controlled laboratory conditions and did not affect seedling emergence in the field. However, seedling survival and growth were improved in plants grown from SA treated seeds (imbibed and encrusted) under field conditions. When SA delivery methods of imbibing and coating were compared, there was no significant difference in survival and growth, showing that seed coating has potential to deliver SA. Effect of intraspecific competition as a result of seedling density was also considered. Seedling survival over the dry summer season was more than double at low seedling density (40 plants/m2) compared to high seedling density (380 plants/m2). Overall, adjustment of seeding rate according to expected emergence combined with the use of salicylic acid via coating could improve seed use efficiency in seed-based restoration.

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A C2H2-Type Zinc-Finger Protein from Millettia pinnata, MpZFP1, Enhances Salt Tolerance in Transgenic Arabidopsis

International Journal of Molecular Sciences ◽

10.3390/ijms221910832 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10832

Author(s):

Zhonghua Yu ◽

Hao Yan ◽

Ling Liang ◽

Yi Zhang ◽

Heng Yang ◽

...

Keyword(s):

Salt Stress ◽

Zinc Finger ◽

Zinc Finger Protein ◽

Seedling Survival ◽

Germination Rate ◽

Biomass Accumulation ◽

Plant Responses ◽

Finger Protein ◽

Millettia Pinnata ◽

Mangrove Associate

C2H2 zinc finger proteins (ZFPs) play important roles in plant development and response to abiotic stresses, and have been studied extensively. However, there are few studies on ZFPs in mangroves and mangrove associates, which represent a unique plant community with robust stress tolerance. MpZFP1, which is highly induced by salt stress in the mangrove associate Millettia pinnata, was cloned and functionally characterized in this study. MpZFP1 protein contains two zinc finger domains with conserved QALGGH motifs and targets to the nucleus. The heterologous expression of MpZFP1 in Arabidopsis increased the seeds’ germination rate, seedling survival rate, and biomass accumulation under salt stress. The transgenic plants also increased the expression of stress-responsive genes, including RD22 and RD29A, and reduced the accumulation of reactive oxygen species (ROS). These results indicate that MpZFP1 is a positive regulator of plant responses to salt stress due to its activation of gene expression and efficient scavenging of ROS.

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Seed-germination response of Leymus chinensis to cold stratification in a range of temperatures, light and low water potentials under salt and drought stresses

Crop and Pasture Science ◽

10.1071/cp16402 ◽

2017 ◽

Vol 68 (2) ◽

pp. 188 ◽

Cited By ~ 7

Author(s):

Jixiang Lin ◽

Yujie Shi ◽

Shuang Tao ◽

Xingyang Yu ◽

Dafu Yu ◽

...

Keyword(s):

Drought Stress ◽

Seed Germination ◽

Drought Tolerance ◽

Northeast China ◽

Germination Percentage ◽

Leymus Chinensis ◽

Grass Species ◽

Cold Stratification ◽

Effective Measure ◽

Salt And Drought Stresses

Leymus chinensis has important forage value and is considered a useful grass species for grassland restoration in Northeast China. However, little information exists concerning the germination responses of this species to interactions of cold stratification, light, temperature and low water potential caused by salinity and drought. Experiments were conducted in growth chambers, and the results showed that in all conditions of light, temperature and water stresses, the germination percentages of cold-stratified seeds were higher than of non-stratified seeds. Light had an inhibitory effect on germination percentage under both non-saline and salt stress conditions; darkness is beneficial for germination of this species. In addition, seeds germinated much better under alternating temperature regimes than under constant temperatures. Both salt and drought stresses decreased the germination percentage of Leymus chinensis, but the reductions under drought stress were much greater. Moreover, after being transferred to distilled water, most non-germinated seeds under drought stress germinated well, and the total percentage reached that of the non-saline condition level. Therefore, cold stratification is an effective measure to increase seed germination and salt or drought tolerance, especially in darkness. We conclude that Leymus chinensis has definite salt and drought tolerance during the germination stage and it is a promising species for the restoration of deteriorated grassland in Northeast China.

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Seed Germination and Physiological Characteristics of Amaranthus mangostanus L. under Drought Stress

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.183-185.1071 ◽

2011 ◽

Vol 183-185 ◽

pp. 1071-1074

Author(s):

Yong Dong Sun ◽

Xiao Hua Du ◽

Wen Jie Zhang ◽

Li Sun ◽

Ran Li

Keyword(s):

Drought Stress ◽

Seed Germination ◽

Germination Rate ◽

Proline Content ◽

Shoot Length ◽

Physiological Characteristics ◽

Sod Activity ◽

Peg 6000 ◽

Mda Content ◽

Effects Of Drought

Effects of drought stress on the seed germination and physiological characteristics of amaranth were investigated. The results were as follows: the germination rate and germination potential of amaranth decreased with the increasing of PEG-6000 concentrations. Meanwhile, the root length, shoot length and peroxidase (POD) activity were significantly increased at lower PEG-6000 concentrations, but then decreased with the increasing of PEG-6000. Malondialdehyde (MDA) content, proline content and superoxide dismutase (SOD) activity were all significantly increased under drought stress, and reached the top at 20% PEG-6000. These findings indicated that amaranth tolerates drought stress through increasing the activities of SOD and POD and accumulating proline content.

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Identification and fine mapping of qGR6.2, a novel locus controlling rice seed germination under salt stress

BMC Plant Biology ◽

10.1186/s12870-020-02820-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Peng Zeng ◽

Peiwen Zhu ◽

Luofeng Qian ◽

Xumei Qian ◽

Yuxin Mi ◽

...

Keyword(s):

Salt Stress ◽

Seed Germination ◽

Candidate Genes ◽

Germination Rate ◽

Tyrosine Phosphatase ◽

Rice Seed ◽

Microarray Database ◽

Family Protein ◽

Germination Traits ◽

Causal Candidate

Abstract Background Rice growth is frequently affected by salinity. When exposed to high salinity, rice seed germination and seedling establishment are significantly inhibited. With the promotion of direct-seeding in Asia, improving rice seed germination under salt stress is crucial for breeding. Results In this study, an indica landrace Wujiaozhan (WJZ) was identified with high germinability under salt stress. A BC1F2 population derived from the crossing WJZ/Nip (japonica, Nipponbare)//Nip, was used to quantitative trait loci (QTL) mapping for the seed germination rate (GR) and germination index (GI) under H2O and 300 mM NaCl conditions. A total of 13 QTLs were identified, i.e. ten QTLs under H2O conditions and nine QTLs under salt conditions. Six QTLs, qGR6.1, qGR8.1, qGR8.2, qGR10.1, qGR10.2 and qGI10.1 were simultaneously identified under two conditions. Under salt conditions, three QTLs, qGR6.2, qGR10.1 and qGR10.2 for GR were identified at different time points during seed germination, which shared the same chromosomal region with qGI6.2, qGI10.1 and qGI10.2 for GI respectively. The qGR6.2 accounted for more than 20% of phenotypic variation under salt stress, as the major effective QTL. Furthermore, qGR6.2 was verified via the BC2F2 population and narrowed to a 65.9-kb region with eleven candidate genes predicted. Based on the microarray database, five candidate genes were found with high transcript abundances at the seed germination stage, of which LOC_Os06g10650 and LOC_Os06g10710 were differentially expressed after seed imbibition. RT-qPCR results showed the expression of LOC_Os06g10650 was significantly up-regulated in two parents with higher levels in WJZ than Nip during seed germination under salt conditions. Taken together, it suggests that LOC_Os06g10650, encoding tyrosine phosphatase family protein, might be the causal candidate gene for qGR6.2. Conclusions In this study, we identified 13 QTLs from a landrace WJZ that confer seed germination traits under H2O and salt conditions. A major salt-tolerance-specific QTL qGR6.2 was fine mapped to a 65.9-kb region. Our results provide information on the genetic basis of improving rice seed germination under salt stress by marker-assisted selection (MAS).

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Isolation and Functional Characterization of a Salt-Responsive Calmodulin-Like Gene MpCML40 from Semi-Mangrove Millettia pinnata

International Journal of Molecular Sciences ◽

10.3390/ijms22073475 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3475

Author(s):

Yi Zhang ◽

Jianzi Huang ◽

Qiongzhao Hou ◽

Yujuan Liu ◽

Jun Wang ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Transgenic Plants ◽

Heterologous Expression ◽

Germination Rate ◽

Functional Characterization ◽

Normal Growth ◽

Growth Conditions ◽

Yeast Cells ◽

Millettia Pinnata

Salt stress is a major increasing threat to global agriculture. Pongamia (Millettia pinnata), a semi-mangrove, is a good model to study the molecular mechanism of plant adaptation to the saline environment. Calcium signaling pathways play critical roles in the model plants such as Arabidopsis in responding to salt stress, but little is known about their function in Pongamia. Here, we have isolated and characterized a salt-responsive MpCML40, a calmodulin-like (CML) gene from Pongamia. MpCML40 protein has 140 amino acids and is homologous with Arabidopsis AtCML40. MpCML40 contains four EF-hand motifs and a bipartite NLS (Nuclear Localization Signal) and localizes both at the plasma membrane and in the nucleus. MpCML40 was highly induced after salt treatment, especially in Pongamia roots. Heterologous expression of MpCML40 in yeast cells improved their salt tolerance. The 35S::MpCML40 transgenic Arabidopsis highly enhanced seed germination rate and root length under salt and osmotic stresses. The transgenic plants had a higher level of proline and a lower level of MDA (malondialdehyde) under normal and stress conditions, which suggested that heterologous expression of MpCML40 contributed to proline accumulation to improve salt tolerance and protect plants from the ROS (reactive oxygen species) destructive effects. Furthermore, we did not observe any measurable discrepancies in the development and growth between the transgenic plants and wild-type plants under normal growth conditions. Our results suggest that MpCML40 is an important positive regulator in response to salt stress and of potential application in producing salt-tolerant crops.

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