Effects of vertically heterogeneous soil salinity on tomato photosynthesis and related physiological parameters

Journal of Plant Interactions

et al. 2019

Self Cite

The experiments were conducted on tomato plants to study the interactive responses of water levels (W 70% : 70% of water consumption and W 90% : 90% water consumption) and nitrogen rates (N 100% : 100% of recommended and N 80% :80% of N 1.0) under two straw mulching conditions (NS; no straw introduced and WS: with buried straw layer) on growth and physiological parameters for two fruit growing years to assess the interactive responses of fertigation under buried straw layer on the changes in plant fresh and dry biomass, roots biomass, photosynthesis rate (P N), stomatal conductance (G S) and chlorophyll fluorescence of tomato plants. Buried straw layer was proved to improve plant biomass, photosynthesis rate and other physiological traits such as chlorophyll contents (Chl), maximum electron transport rate (ETRmax), maximum quantum yield (F V /F M) and G S under the lower fertilizer (N 80%) and irrigation levels (W 70%). However, increasing fertilizer and irrigation level decreased these parameters significantly (p < .05 to p < .001) under buried straw layer. Conversely, increased fertilizer (N 100%) and irrigation (W 90%) levels increased these parameters significantly (p < .05 to p < .001) under no straw condition. The overall findings revealed that buried straw layer could relieve stress developed by limited irrigation water and fertilizer and benefit plant growth, physiological parameters and fruit yield of tomato plant.

Section: Discussionsupporting

confidence: 92%

The interactive responses of fertigation levels under buried straw layer on growth, physiological traits and fruit yield in tomato plant

Rasool

Guo

Journal of Plant Interactions

et al. 2019

Self Cite

“…These observations were confirmed in alfalfa by Xiong et al [39]. With respect to photosynthesis, we noted that, compared with those in the uniform saline group, the net photosynthesis, chlorophyll content, and stomatal conductance in the nonuniform saline group increased, which was in line with the results of Chen et al’s study [36]. Furthermore, the transpiration rate was reduced as a result of increased levels of salt stress [40, 41].…”

Section: Discussionsupporting

confidence: 90%

“…The spatial distribution of salinity is rarely uniform in soils [36]. Compared with those focusing on uniform salinity conditions, studies related to nonuniform salinity conditions are lacking.…”

Section: Discussionmentioning

confidence: 99%

Heterogeneous root zone salinity mitigates salt injury to Sorghum bicolor (L.) Moench in a split-root system

Zhang

et al. 2019

PLoS ONE

The heterogeneous distribution of soil salinity across the rhizosphere can moderate salt injury and improve sorghum growth. However, the essential molecular mechanisms used by sorghum to adapt to such environmental conditions remain uncharacterized. The present study evaluated physiological parameters such as the photosynthetic rate, antioxidative enzyme activities, leaf Na+ and K+ contents, and osmolyte contents and investigated gene expression patterns via RNA sequencing (RNA-seq) analysis under various conditions of nonuniformly distributed salt. Totals of 5691 and 2047 differentially expressed genes (DEGs) in the leaves and roots, respectively, were identified by RNA-seq under nonuniform (NaCl-free and 200 mmol·L-1 NaCl) and uniform (100 mmol·L-1 and 100 mmol·L-1 NaCl) salinity conditions. The expression of genes related to photosynthesis, Na+ compartmentalization, phytohormone metabolism, antioxidative enzymes, and transcription factors (TFs) was enhanced in leaves under nonuniform salinity stress compared with uniform salinity stress. Similarly, the expression of the majority of aquaporins and essential mineral transporters was upregulated in the NaCl-free root side in the nonuniform salinity treatment, whereas abscisic acid (ABA)-related and salt stress-responsive TF transcripts were more abundant in the high-saline root side in the nonuniform salinity treatment. In contrast, the expression of the DEGs identified in the nonuniform salinity treatment remained virtually unaffected and was even downregulated in the uniform salinity treatment. The transcriptome findings might be supportive of the increased photosynthetic rate, reduced Na+ levels, increased antioxidative capability in the leaves and, consequently, the growth recovery of sorghum under nonuniform salinity stress as well as the inhibited sorghum growth under uniform salinity conditions. The increased expression of salt resistance genes activated in response to the nonuniform salinity distribution implied that the cross-talk between the nonsaline and high-saline sides of the roots exposed to nonuniform salt stress is potentially regulated.

“…The root systems of many species exhibit morphological plasticity, which increases the ratio of fine roots and improves the contact area so that they can absorb more nutrients in low-nutrient soils ( Zhang et al, 2010 ; Li et al, 2014 ; Mai et al, 2018 ). Like nutrients, various salts show great spatial and temporal variations in their concentrations in saline-alkali soil ( Chen et al, 2019 ). The patterns of salt distribution in the soil strongly affect the spatial distribution of plants, as well as the configuration, length, and size of their root systems.…”

Section: Introductionmentioning

confidence: 99%

Root Morphology and Rhizosphere Characteristics Are Related to Salt Tolerance of Suaeda salsa and Beta vulgaris L.

Zhao

et al. 2021

Front. Plant Sci.

Halophytes are capable of resisting salinity, and their root system is the part in direct contact with the saline soil environment. The aim of this study was to compare the responses of root morphology and rhizosphere characteristics to salinity between a halophyte, Suaeda salsa (suaeda), and a glycophyte, Beta vulgaris L. (sugar beet). The soil salt content was set to four levels (0.7, 1.2, 1.7, and 2.7%) by NaCl-treated plants. We investigated the soil pH, EC, nutrients and soil, plant ion (Na+, Cl−, K+, and Mg2+) concentration to evaluate the rhizospheric processes, and salt tolerance of suaeda by the root mat method. The highest biomass was in the 1.2% salt level for suaeda and in the 0.7% salt level for sugar beet. The root length and root surface area of suaeda showed similar trends to biomass, but the root diameter decreased by 11.5–17.9% with higher salinity. The Na+, Cl−, and K+ accumulations in the shoot of suaeda displayed higher than that in sugar beet, while the Mg2+ accumulation was lower in suaeda than that in sugar beet. High salinity resulted in increased pH and EC values in the rhizosphere for suaeda, but lower values of these parameters for sugar beet. Under high salinity, the Olsen phosphorus content was 0.50 g·kg−1 and 0.99 g·kg−1 higher in the rhizosphere than in the non-rhizosphere for suaeda and sugar beet. We concluded that the two species [halophyte, Suaeda salsa (suaeda), and a glycophyte, B. vulgaris L. (sugar beet)] showed diverse approaches for nutrient absorption under salinity stress. Suaeda altered its root morphology (smaller root diameter and longer roots) under salt stress to increase the root surface area, while sugar beet activated rhizospheric processes to take up more nutrients.