Soil pH-dependent nitrogen stimulation of plant biomass: magnesium and calcium as key constraints.

Anthropogenic nitrogen (N) deposition can alleviate N limitation and stimulate plant growth in many terrestrial ecosystems. While theoretical models often emphasize phosphorus limitations as a constraint on this positive N effect, the impact of N-induced magnesium (Mg) and calcium (Ca) deficits due to soil acidification has been largely overlooked. Here, we synthesized data from 243 experiments across diverse terrestrial ecosystems to investigate the role of Mg and Ca in plant biomass responses to N addition.

Changes of endophytic microbial community in roots under heat stress and its correlation with leaf physiological indicators.

Introduction: The response mechanism of Rhododendron simsii and its endophytic microorganism to heat stress is still unclear.

Methods: The light incubator was used to set the temperature gradients, and the control (CK) was (day/night: 14/10 h) 25/22°C, the moderate-heat-stress (MHS) was 35/30°C and the high-heat-stress (HHS) was 40/35°C.

Results: Compared with CK, MHS significantly increased the contents of malondialdehyde, hydrogen peroxide, proline, and soluble sugar, as well as the activities of catalase and peroxidase in leaf, while HHS increased the activities of ascorbate peroxidase, and decreased chlorophyll content.

Changes and Correlation Between Physiological Characteristics of and Soil Microbial Communities Under Heat Stress.

The relationship between and its soil microbial community under heat stress was not clear. In this study, the effects of heat stress on the physiological characteristics, soil physicochemical properties and soil microbial community structure of were investigated. The experimental control (CK) was set as day/night (14/10 h) 25/20°C and experimental treatments were set as light heat stress (LHS) 35/30°C and high heat stress (HHS) 40/35°C.