SEED GERMINATION - Cold Tolerance in Rice Cultivation - page 15

sorted into 10 categories by their functions metabolism, oxygen-
detoxifying, protein processing/degradation, stress/defense,
energy and others. This suggested that there are multiple
regulations in embryo during seed germination (Kim et al.
2009) (Table 4).

Table 4 Peak activities of enzymes during germination.

Enzyme Peak activity (Approx.)

Phosphomonoesterase 5 to 7 DAG

Phosphodiesterase ”

Esterase ”

Lipase ”

Peroxidase ”

Catalase ”

Beta-glucosidase ”

Alpha-galactosidase ”

Beta-galactosidase ”

Beta-1, 3-glycanase 7 to 10 DAG

Phytase ”

ATPase ”

Pyrophosphatase ”

Protease 5 to 6 DAG

Pullulanase (R-Enzyme) 7 to 8 DAG

Aleurone is a living tissue surrounding the starchy
endosperm and synthesizing key enzymes for germination.
The single layer aleurone (unlike multiple layers in barley) is
diffi cult to be separated in rice seed manually, but aleurone
rich bran might be selected as substitute. 43 unique proteins
with enzymatic activity (30%), signaling/regulation proteins
(30%), storage protein (30%), transfer (5%) and structural (5%)
were identifi ed (Ferrari et al. 2009).