Xylem hydraulic conductivity and embolism in riparian plants and their responses to drought stress in desert of Northwest China

Ecohydrology ◽  
2013 ◽  
Vol 6 (6) ◽  
pp. 984-993 ◽  
Author(s):  
Honghua Zhou ◽  
Yaning Chen ◽  
Weihong Li ◽  
Mubarek Ayup
2020 ◽  
Vol 53 (2) ◽  
Author(s):  
Guanglong Zhu ◽  
Lifeng Gu ◽  
Yu Shi ◽  
Huize Chen ◽  
Yuqian Liu ◽  
...  

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1117
Author(s):  
Wei Chen ◽  
Panpan Meng ◽  
Huan Feng ◽  
Chunyan Wang

Catalpa bungei C.A.Mey. is a common ornamental timber species. Its survival and growth are greatly affected by water scarcity in arid and semi-arid areas of Northwest China. Evidence suggests arbuscular mycorrhizal fungus (AMF) may improve plant drought resistance. However, there is limited information on the systematic effects of AMF on drought resistance in C. bungei seedlings. Here, a pot experiment was used to explore the effects of inoculation with the AMF Rhizophagus intraradices on the growth and physiological performance of C. bungei under different water treatment conditions. Three water levels and two mycorrhizal inoculation treatments were used with factorial design. The results showed that drought stress noticeably affected the growth and physiological performance of C. bungei seedlings. However, inoculation with R. intraradices significantly ameliorated the growth, and alleviated the effects of drought stress. The growth parameters of AMF-inoculated seedlings significantly increased regardless of water status. AMF changed the biomass allocation in seedlings by reducing the root mass ratio (RMR) and root/shoot ratio. AMF-inoculated seedlings displayed higher gas exchange parameters, photosynthetic pigment concentrations, specific leaf area (SLA), but lower specific leaf weight (SLW), regardless of water status. AMF alleviated drought-induced oxidative stress by attenuating the excess generation of reactive oxygen species (ROS), especially H2O2 and O2−, in leaves. Inoculation with AMF under drought stress also dramatically augmented indole-3-acetic acid (IAA) and gibberellins (GA3) levels and the IAA/abscisic acid (ABA) and GA3/ABA ratios, but reduced ABA and zeatin (ZT) levels in leaves. AMF symbiosis improved root morphology and promoted the absorption of nitrogen (N) and phosphorus (P) in seedlings. We conclude that inoculation with R. intraradices is potentially useful for afforestation and cultivation of C. bungei in Northwest China. Furthermore, AMF improved soil structure by increasing the glomalin-related soil protein (GRSP) contents and the proportion of macro-aggregates (0.25–0.5 mm) in the rhizosphere soil.


2016 ◽  
Vol 24 (8) ◽  
pp. 2049-2062 ◽  
Author(s):  
Jinxi Song ◽  
Weiwei Jiang ◽  
Shaofeng Xu ◽  
Guotao Zhang ◽  
Liping Wang ◽  
...  

2014 ◽  
Vol 614 ◽  
pp. 653-657 ◽  
Author(s):  
Xiao Xue Shen ◽  
Min Wei Chai ◽  
Rui Li Li ◽  
Guo Yu Qiu

A study quantifying the role of the interactive effects of salt and drought stresses, generally co-occurred in deserts, on seed germination in Ammopiptanthus mongolicus was conducted in a constant temperature incubator. The experiment consisted of seven levels of salinity stress (0, 0.3, 0.6, 0.9, 1.2, 1.5 and 1.8% NaCl) as well as six drought stress levels (0, -0.2, -0.4, -0.8, -1.6 and-2.0 MPa PEG). Accordant to our expectations, the interactive effects of salinity and drought stresses were additive on seed germination percentages, germination rate, and germination energy; significant decreases were seen in all of them in response to increases in salt and/or drought stresses. Furthermore, regression coefficients of salinity (β1) were higher than drought (β2), indicating that salinity was the first factor, and drought was secondary for salt and drought mixed stresses.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hailun Yu ◽  
Xueyong Zhao ◽  
Wenda Huang ◽  
Jin Zhan ◽  
Yuanzheng He

Extensive studies have shown that the success of invasive plants in large environmental gradients can be partly attributed to related factors, including phenotypic plasticity and rapid evolution. To enhance their ability to compete and invade, invasive plants often show higher morphological and physiological plasticity to adapt to different habitat conditions. In the past two decades, invasive species have expanded to some new habitats in North and Northwest China, including arid oasis agricultural zones, which are disturbed by human activities, and the ecosystem itself is very fragile. To evaluate the ecological adaptability of invasive plants widely distributed in North and Northwest China, we studied the physiological response and tolerance mechanism of different geographical populations of Solanum rostratum Dunal to different drought-stress gradients in extremely arid regions (Xinjiang population) and semi-arid regions (Inner Mongolia population). The results showed that with the aggravation of drought stress, S. rostratum from different geographical populations adopted different physiological mechanisms to drought stress. Xinjiang population was mostly affected by root/shoot ratio and chlorophyll fluorescence characteristics, showing higher plasticity in the net and total photosynthetic rates, while the Inner Mongolia population mainly relied on the accumulation of osmotic adjustment substances, higher leaf dry matter content, and increased malondialdehyde to cope with drought stress. Based on these results, we concluded that the physiological responses of S. rostratum invading different habitats in northern China to drought stress were significantly different. The drought resistance of the Xinjiang population was higher than that of the Inner Mongolia population. In general, S. rostratum can be widely adapted to both harsh and mild habitats through phenotypic plasticity, threatening agricultural production and ecological environment security in northern China.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chao He ◽  
Wenquan Wang ◽  
Junling Hou ◽  
Xianen Li

This study aimed to explore dark septate endophytes (DSE) that may improve the cultivation of medicinal plants in arid ecosystems. We isolated and identified eight DSE species (Acremonium nepalense, Acrocalymma vagum, Alternaria chartarum, Alternaria chlamydospora, Alternaria longissima, Darksidea alpha, Paraphoma chrysanthemicola, and Preussia terricola) colonizing the roots of wild licorice (Glycyrrhiza uralensis) in the desert areas of northwest China. Moreover, we investigated the osmotic stress tolerance of the DSE using pure culture, along with the performance of licorice plants inoculated with the DSE under drought stress in a growth chamber, respectively. Here, five species were first reported in desert habitats. The osmotic-stress tolerance of DSE species was highly variable, A. chlamydospora and P. terricola increased the total biomass and root biomass of the host plant. All DSE except A. vagum and P. chrysanthemicola increased the glycyrrhizic acid content; all DSE except A. chartarum increased the glycyrrhizin content under drought stress. DSE × watering regimen improved the glycyrrhizic acid content, soil organic matter, and available nitrogen. Structural equation model analysis showed that DSE × watering regimen positively affected soil organic matter, and total biomass, root length, glycyrrhizic acid, and glycyrrhizin (Shapotou site); and positively affected soil organic matter, available phosphorus, and glycyrrhizin (Minqin site); and positively affected the root length (Anxi site). DSE from the Shapotou site accounted for 8.0, 13.0, and 11.3% of the variations in total biomass, root biomass, and active ingredient content; DSE from the Minqin site accounted for 6.6 and 8.3% of the variations in total biomass and root biomass; DSE from the Anxi site accounted for 4.2 and 10.7% of the variations in total biomass and root biomass. DSE × watering regimen displayed a general synergistic effect on plant growth and active ingredient contents. These findings suggested that the DSE–plant interactions were affected by both DSE species and DSE originating habitats. As A. chlamydospora and P. terricola positively affected the total biomass, root biomass, and active ingredient content of host plants under drought stress, they may have important uses as promoters for the cultivation of licorice in dryland agriculture.


2020 ◽  
Vol 40 (9) ◽  
pp. 1147-1164
Author(s):  
Roman Gebauer ◽  
Roman Plichta ◽  
Josef Urban ◽  
Daniel Volařík ◽  
Martina Hájíčková

Abstract Spring drought is becoming a frequently occurring stress factor in temperate forests. However, the understanding of tree resistance and resilience to the spring drought remains insufficient. In this study, European beech (Fagus sylvatica L.) seedlings at the early stage of leaf development were moderately and severely drought stressed for 1 month and then subjected to a 2-week recovery period after rewatering. The study aimed to disentangle the complex relationships between leaf gas exchange, vascular anatomy, tree morphology and patterns of biomass allocation. Stomatal conductance decreased by 80 and 85% upon moderate and severe drought stress, respectively, which brought about a decline in net photosynthesis. However, drought did not affect the indices of slow chlorophyll fluorescence, indicating no permanent damage to the light part of the photosynthetic apparatus. Stem hydraulic conductivity decreased by more than 92% at both drought levels. Consequently, the cambial activity of stressed seedlings declined, which led to lower stem biomass, reduced tree ring width and a lower number of vessels in the current tree ring, these latter also with smaller dimensions. In contrast, the petiole structure was not affected, but at the cost of reduced leaf biomass. Root biomass was reduced only by severe drought. After rewatering, the recovery of gas exchange and regrowth of the current tree ring were observed, all delayed by several days and by lower magnitudes in severely stressed seedlings. The reduced stem hydraulic conductivity inhibited the recovery of gas exchange, but xylem function started to recover by regrowth and refilling of embolized vessels. Despite the damage to conductive xylem, no mortality occurred. These results suggest the low resistance but high resilience of European beech to spring drought. Nevertheless, beech resilience could be weakened if the period between drought events is short, as the recovery of severely stressed seedlings took longer than 14 days.


Sign in / Sign up

Export Citation Format

Share Document