<Ul> <Li> Plant peptide hormones--encompasses all small secreted peptides that are involved in cell - to - cell signaling . These small peptide hormones play crucial roles in plant growth and development, including defense mechanisms, the control of cell division and expansion, and pollen self - incompatibility . The small peptide CLE25 is known to act as a long - distance signal to communicate water stress sensed in the roots to the stomata in the leaves . </Li> <Li> Polyamines--are strongly basic molecules with low molecular weight that have been found in all organisms studied thus far . They are essential for plant growth and development and affect the process of mitosis and meiosis . </Li> <Li> Nitric oxide (NO)--serves as signal in hormonal and defense responses (e.g. stomatal closure, root development, germination, nitrogen fixation, cell death, stress response). NO can be produced by a yet undefined NO synthase, a special type of nitrite reductase, nitrate reductase, mitochondrial cytochrome c oxidase or non enzymatic processes and regulate plant cell organelle functions (e.g. ATP synthesis in chloroplasts and mitochondria). </Li> <Li> Karrikins--are not plant hormones as they are not produced by plants themselves but are rather found in the smoke of burning plant material . Karrikins can promote seed germination in many species . The finding that plants which lack the receptor of karrikin receptor show several developmental phenotypes (enhanced biomass accumulation and increased sensitivity to drought) have lead some to speculate on the existence of an as yet unidentified karrikin - like endogenous hormone in plants . The cellular karrikin signalling pathway shares many components with the strigolactone signalling pathway . </Li> <Li> Triacontanol--a fatty alcohol that acts as a growth stimulant, especially initiating new basal breaks in the rose family . It is found in alfalfa (lucerne), bee's wax, and some waxy leaf cuticles . </Li> </Ul> <Li> Plant peptide hormones--encompasses all small secreted peptides that are involved in cell - to - cell signaling . These small peptide hormones play crucial roles in plant growth and development, including defense mechanisms, the control of cell division and expansion, and pollen self - incompatibility . The small peptide CLE25 is known to act as a long - distance signal to communicate water stress sensed in the roots to the stomata in the leaves . </Li> <Li> Polyamines--are strongly basic molecules with low molecular weight that have been found in all organisms studied thus far . They are essential for plant growth and development and affect the process of mitosis and meiosis . </Li> <Li> Nitric oxide (NO)--serves as signal in hormonal and defense responses (e.g. stomatal closure, root development, germination, nitrogen fixation, cell death, stress response). NO can be produced by a yet undefined NO synthase, a special type of nitrite reductase, nitrate reductase, mitochondrial cytochrome c oxidase or non enzymatic processes and regulate plant cell organelle functions (e.g. ATP synthesis in chloroplasts and mitochondria). </Li>

What is role of growth harmone in plant movement