Understanding Plant Community Responses to Combinations of Biotic and Abiotic Factors in Different Phases of the Plant Growth Cycle

Exogenous silicon (Si) can enhance plant resistance to various abiotic factors causing osmotic stress. The objective of this research was to evaluate the application of 1 and 2 mM Si to plants under normal conditions and under osmotic stress. Morelos A-98 rice seedlings, were treated with 1 and 2 mM SiO2 for 28 d. Subsequently, half of the plants were subjected to osmotic stress with the addition of 10% polyethylene glycol (PEG) 8000; and continued with the addition of Si (0, 1 and 2 mM SiO2) for both conditions. The application of Si under both conditions increased chlorophyll b in leaves, root volume, as well as fresh and dry biomass of roots. Interestingly, the number of tillers, shoot fresh and dry biomass, shoot water content, concentration of total chlorophyll, chlorophyll a/b ratio, and the concentration of total sugars and proline in shoot increased with the addition of Si under osmotic stress conditions. The addition of Si under normal conditions decreased the concentration of sugars in the roots, K and Mn in roots, and increased the concentration of Fe and Zn in shoots. Therefore, Si can be used as a potent inorganic biostimulant in rice Morelos A-98 since it stimulates plant growth and modulates the concentration of vital biomolecules and essential nutrients.

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Global quantitative synthesis of effects of biotic and abiotic factors on stemflow production in woody ecosystems

Global Ecology and Biogeography ◽

10.1111/geb.13322 ◽

2021 ◽

Author(s):

Yafeng Zhang ◽

Xinping Wang ◽

Yanxia Pan ◽

Rui Hu ◽

Ning Chen

Keyword(s):

Abiotic Factors ◽

Biotic And Abiotic Factors ◽

Quantitative Synthesis

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Flow cytometric measurements as a proxy for sporulation intensity in the cultured macroalga Ulva (Chlorophyta)

Botanica Marina ◽

10.1515/bot-2020-0050 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Omri Nahor ◽

Cristina F. Morales-Reyes ◽

Gianmaria Califano ◽

Thomas Wichard ◽

Alexander Golberg ◽

...

Keyword(s):

Flow Cytometry ◽

Life Cycle ◽

Abiotic Factors ◽

Physiological Status ◽

Seaweed Cultivation ◽

Reproductive Growth ◽

Biotic And Abiotic Factors ◽

Flow Cytometric ◽

Abiotic Stimuli ◽

Fundamental Shift

Abstract Controlling the life cycle of the green macroalga Ulva (Chlorophyta) is essential to maintain its efficient aquaculture. A fundamental shift in cultivation occurs by transforming the thallus cells into gametangia and sporangia (sporulation), with the subsequent release of gametes and zoids. Sporulation occurrence depends on algal age and abiotic stimuli and is controlled by sporulation inhibitors. Thus, quantification of sporulation intensity is critical for identifying the biotic and abiotic factors that influence the transition to reproductive growth. Here, we propose to determine the sporulation index by measuring the number of released gametes using flow cytometry, in proportion to the total number of thallus cells present before the occurrence of the sporulation event. The flow cytometric measurements were validated by manually counting the number of released gametes. We observed a variation in the autofluorescence levels of the gametes which were released from the gametangia. High autofluorescence level correlated to phototactically active behaviour of the gametes. As autofluorescence levels varied between different groups of gametes related to their mobility, flow cytometry can also determine the physiological status of the gametes used as feedstock in seaweed cultivation.

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