Atmospheric N deposition alleviates the unfavorable effects of drought on wheat growth

Abstract

Drought and atmospheric nitrogen deposition (AND) become increasingly serious in recent decades owing to the progressively rising anthropogenic activities. Thus, it is significant to assess the effects of combined drought and AND on plant morphological and physiological performance (MorPhyPer) to better elucidate the mechanisms that drive the successful plant life-history strategies under the combined drought and AND. The objective of this study is to evaluate the combined drought [imitated by polyethylene glycol-6000 (PEG 6000) solution] with different degrees and AND [a mixed N with a 1: 1: 1 ratio of NH 4-N: NO 3-N: CO(NH 2) 2-N] with different concentrations on MorPhyPer of wheat (Triticum aestivum L.) via the garden-pot cultivation under the condition with natural light for nearly sixty days. Results showed that drought dramatically reduced MorPhyPer of wheat. This phenomenon may be attributed to the gradually enhanced osmotic pressure generated by the dehydrated condition, the enhanced degrees of reactive oxygen species, the raised level of plant cell cytoplasm membrane peroxidation, and/or the downgraded plant enzymatic defensive ability. AND notably improved MorPhyPer of wheat mostly owing to the relieved N deficiencies. The combined drought and AND antagonistically affect plant supporting ability, leaf photosynthetic area, and belowground growing competitiveness of wheat. The reason may be due to the increased belowground moisture content under the combined drought and AND which can improve the efficiency and capacity of nutrients absorption (mainly absorb more N nutrients) by root and transport to the aboveground portion and subsequently raise the level of drought resistance. The reason may be also attributed to the enhanced leaf photosynthetic area which can capture more sunlight and increase the tolerance to the adverse environment. Accordingly, AND notably alleviated the unfavorable effects of drought on MorPhyPer of wheat basically.

Drought stress intensifies the phytotoxicity of five Asteraceae exotic invasive plants

“…Drought stress, particularly heavy of drought stress, distinctly decreased the competitiveness for sunlight capture and the competitiveness for water and inorganic salt absorption of L. sativa. Sunlight, water, and inorganic salt may be the three most critical ingredients that are vital for plant growth (Xiao et al 2015;Borsai et al 2018;Cheng et al 2020;Wang et al 2021). The results match expectations.…”

“…As one of the main detrimental abiotic stress factors for plant growth presently, drought stress can impose harmful effects on plant growth, particularly on the morphology and metabolism of plants (Toscano et al 2017;Naidoo and Naidoo 2018;Cheng et al 2020;Wu et al 2021). The secondary metabolism and the secretion of secondary metabolites may be changed under drought stress (Kleinwaechter et al 2015;Chaeikar et al 2020;Talbi et al 2020;Jiao et al 2021).…”

Is the Invasive Plant Amaranthus spinosus L. More Competitive than the Native Plant A. tricolor L. When Exposed to Acid Deposition with Different Sulfur–Nitrogen Ratios?

“…The functional indices of the two Amaranthus species included (I) plant height (representing the competitiveness for sunlight acquisition), (II) ground diameter (representing plant supporting ability), (III) leaf size (characterized as leaf length and width, representing leaf photosynthetic area), (IV) green leaf area (representing leaf photosynthetic area), (V) leaf thickness (representing leaf supporting ability), (VI) single-leaf wet and dry weights (representing leaf growing competitiveness), (VII) leaf water content (representing leaf moisture content), (VIII) specific leaf area (representing leaf resource use efficiency and acquisition capacity), (IX) leaf chlorophyll and nitrogen concentrations (representing leaf photosynthetic capacity), (X) plant aboveground wet and dry weights (representing aboveground growing competitiveness), and (XI) plant aboveground water content (representing aboveground moisture content). The procedures used to determine the functional indices are described in our previous study [27,28].…”