Comparative effects of salt and alkali stress on photosynthesis and root physiology of oat at anthesis

Soil salinization and alkalization frequently co-occur in the grassland, but little information exists concerning the mixed effects of salt-alkaline stress on plant. Jerusalem artichoke is an economically and ecologically important energy crop and also considered as a salt-tolerant species. In this study, we investigated the effects of 12 mixed salt-alkaline conditions on the seedling growth and responses of Jerusalem artichoke to such conditions. The results showed that the seedling growth decreased with the increasing salinity and pH, and the destructive effects were more markedly under the interactions of highest salinity and pH. The Na+, Mg2+ and Ca2+ concentrations were all increased with the increasing salinity and pH, but the K+ kept stable. The Cl- concentration increased when the treatment without alkali salts, and the NO3â€“ and H2PO4- concentrations were decreased with the increasing salinity. Jerusalem artichoke seedlings enhanced organic acids and proline to supply the shortage of inorganic anions and cope with osmotic stress from the high Na+ concentration. Above results show that the toxicity effects of the interactions of salt stress and alkali stress on plant is much greater than that only salt or alkali stress. A better understanding of the seedlings of Jerusalem artichoke under mixed salt-alkali stress conditions should facilitate the effective utilization of this species under such complex environment in Northeast China.

Download Full-text

Metabolic Differences Between Suaeda Salsa and Puccinellia Tenuiflora Under Saline-alkali Stress

10.21203/rs.3.rs-892289/v1 ◽

2021 ◽

Author(s):

Qi Chen ◽

Huansong Xie ◽

Guanyun Wei ◽

Xiaorui Guo ◽

Jian Zhang ◽

...

Keyword(s):

Amino Acids ◽

Phenolic Compounds ◽

Metal Ion ◽

Stress Measurement ◽

Suaeda Salsa ◽

Alkali Stress ◽

Plant Metabolites ◽

Habitat Transformation ◽

Response Strategies ◽

Puccinellia Tenuiflora

Abstract Background: Salinization of soil is an urgent problem that restricts agroforestry production and environment protection. Substantial accumulation of metal ion or high alkaline alters plant metabolites and may even cause plant death. In order to explore the differences in the response strategies between Suaeda salsa (S. salsa) and Puccinellia tenuiflora (P. tenuiflora), two main constructive species that survive in saline-alkali soil, their metabolic differences were characterized.Result: Metabolomics was conducted to study the role of metabolic differences between S. salsa and P. tenuiflora under saline-alkali stress. A total of 68 significantly different metabolites were identified by GC-MS, including 9 sugars, 13 amino acids, 8 alcohols, and 34 acids. A more detailed analysis indicated that P. tenuiflora utilizes sugars more effectively and may be salt-alkali tolerant via sugar consumption while S. salsa mainly utilizes amino acids, alcohols, and acids to resist salt-alkali stress. Measurement of phenolic compounds showed that more C6C3C6-compounds were accumulated in P. tenuiflora while more C6C1-compounds, phenolic compounds that can be used to defense stress as signaling molecules, were accumulated in S. salsa.Conclusion: Our observations suggest that S. salsa resists the toxicity of saline-alkali stress using aboveground organs and P. tenuiflora eliminates the poison of saline-alkali via roots. S. salsa has a stronger ability of habitat transformation and can provide better habitat for other plants.

Download Full-text

Aboveground Herbivory Influences Belowground Defense Responses in Maize

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.765940 ◽

2021 ◽

Vol 9 ◽

Author(s):

Lise Pingault ◽

Saumik Basu ◽

Prince Zogli ◽

W. Paul Williams ◽

Nathan Palmer ◽

...

Keyword(s):

European Corn Borer ◽

Proteinase Inhibitors ◽

Insect Pest ◽

Diabrotica Virgifera Virgifera ◽

Defense Responses ◽

Short Term ◽

Long Distance ◽

Corn Borer ◽

Root Physiology ◽

Aboveground Herbivory

The European corn borer (ECB; Ostrinia nubilalis) is an economically damaging insect pest of maize (Zea mays L.), an important cereal crop widely grown globally. Among inbred lines, the maize genotype Mp708 has shown resistance to diverse herbivorous insects, although several aspects of the defense mechanisms of Mp708 plants are yet to be explored. Here, the changes in root physiology arising from short-term feeding by ECB on the shoot tissues of Mp708 plants was evaluated directly using transcriptomics, and indirectly by monitoring changes in growth of western corn rootworm (WCR; Diabrotica virgifera virgifera) larvae. Mp708 defense responses negatively impacted both ECB and WCR larval weights, providing evidence for changes in root physiology in response to ECB feeding on shoot tissues. There was a significant downregulation of genes in the root tissues following short-term ECB feeding, including genes needed for direct defense (e.g., proteinase inhibitors and chitinases). Our transcriptomic analysis also revealed specific regulation of the genes involved in hormonal and metabolite pathways in the roots of Mp708 plants subjected to ECB herbivory. These data provide support for the long-distance signaling-mediated defense in Mp708 plants and suggest that altered metabolite profiles of roots in response to ECB feeding of shoots likely negatively impacted WCR growth.

Download Full-text