IMPACT OF LIQUID NITROGEN EXPOSURE ON SELECTED BIOCHEMICAL AND STRUCTURAL PARAMETERS OF HYDRATED Phaseolus vulgaris L. SEEDS.
BACKGROUND
It is well known that cryopreserving seeds with high water content is detrimental to survival, but biochemical and structural parameters of cryostored hydrated common bean seeds have not been published.


OBJECTIVE
The objective of this work was to study the effect of liquid nitrogen exposure on selected biochemical and structural parameters of hydrated Phaseolus vulgaris seeds.


METHODS
We cryopreserved seeds at various moisture contents and evaluated: germination; electrolyte leakage; fresh seed weight; levels of chlorophyll pigments, malondialdehyde, other aldehydes, phenolics and proteins; thickness of cotyledon epidermis, parenchyma, and starch storage parenchyma; and radicle and plumule lengths.


RESULTS
Germination was totally inhibited when seeds were immersed in water for 50 min (moisture content of 38%, FW basis) before cryopreservation. The combined effects of seed water imbibition and cryostorage decreased phenolics (free, cell wall-linked, total), chlorophyll a and protein content. By contrast, electrolyte leakage and levels of chlorophyll b and other aldehydes increased as a result of the combination of these two experimental factors. These were the most significant effects observed during exposure of humid seed to liquid nitrogen.


CONCLUSIONS
Further studies are still required to clarify the molecular events taking place in plant cells during cryostorage.
Inaudis
I
Cejas
Maribel
M
Rivas
Lelurlys
L
Nápoles
Pedro
P
Marrero
Lourdes
L
Yabor
Carlos
C
Aragón
Aurora
A
Pérez
Florent
F
Engelmann
Marcos Edel
ME
Martínez-Montero
José Carlos
JC
Lorenzo
D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D018548:Cotyledon / Q000502:physiology; D015925:Cryopreservation / Q000379:methods; D018525:Germination; D008315:Malondialdehyde / Q000032:analysis; D009584:Nitrogen / Q000737:chemistry; D027805:Phaseolus / Q000737:chemistry / Q000254:growth & development*; D010636:Phenols / Q000032:analysis; D012639:Seeds / Q000737:chemistry / Q000254:growth & development*
D010636:Phenols; D002734:Chlorophyll; D008315:Malondialdehyde; C037184:chlorophyll b; D009584:Nitrogen; D000077194:Chlorophyll A