Plant growth modulating

The Rothamsted Carbon Model (RothC) uses a five pool structure, decomposable plant material (DPM), resistant plant materials (RPM), microbial biomass, humified organic matter, and inert organic matter to assess carbon turnover (Coleman and Jenkinson 1996 Guo et al. 2007). The first four pools decompose by first-order kinetics. The decay rate constants are modified by temperature, soil moisture, and indirectly by clay content. RothC does not include a plant growth sub-module, and therefore NHC inputs must be known, estimated, or calculated by inverse modeling. Skjemstad et al. (2004) tested an approach for populating the different pools based on measured values. 

Fermentation products have played a rather minor role in the control of plant diseases. Table VI gives a classification of agents used on plants. These are divided into pesticides and growth modulators. The pesticides are classified as bactericides, fungicides, insecticides, miticides, nematicides and herbicides. There are fermentation products in each of these categories, and these are listed in Table VII. 

FLAVONOID-AUXIN TRANSPORT INTERACTION AND MODULATION OF PLANT GROWTH... 

Biswas, B. B. Roy, P. Plant growth substances as modulators of transcription. Chapter 4, Subcellular Biochemistry, 1978,... 

Kmnersley, A.M. and Lin, F. (2000) Receptor modifiers indicate that 4-aminobutyric acid (GABA) is a potential modulator of ion transport in plants. /. Plant Growth ReguL, 32,65-76. 

While ethylene has been known as a major modulator of plant growth and development for nearly a century [1], extensive studies on its mode of action came later than was the case for most other growth regulators. To a significant extent this was for two reasons firstly it was difficult accurately to measure ethylene production by plants and bioassays were tedious and complicated and secondly because there was some resistance to even recognising ethylene as a hormone, partly because of its small size and simplicity, but largely because it is a gas and did not therefore fit easily with classical conceptions of a hormone. 

The advent of gas chromatography made ethylene the easiest plant growth regulator to measure and the evidence is now overwhelming that ethylene is a major factor in the modulation of plant growth and development under both normal and stress conditions (see e.g. reference [2]). 

Fig. 2 Functions of phytochemicals in plant growth and development. Phytoohemicals play multiple functions in plant growth and development, including pollen tube growth elongation (a), seed coat imposed dormancy reinforcement (b), modulation of lignin biosynthesis (c), regulation of auxin polar transport (d), shoot/root gravitropic responses (e), root nodulation (f) and allelopathy (g)...

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