CHANGES OF ELECTROPHORETIC ALBUMIN PATTERNS IN GERMINATING SEED OF FIVE DIVERSE PISUM LINES

PNL Volume 14

1982

RESEARCH REPORTS

CHANGES OF ELECTROPHORETIC ALBUMIN PATTERNS IN GERMINATING SEED OF

FIVE DIVERSE PISUM LINES¹

Jakubek, M. and J. Przybylska Institute of Plant Genetics

Polish Academy of Sciences

Poznan, Poland

An electrophoretic analysis of seed albumins of lines within the

genus Pisum revealed five distinct protein patterns which differed in

number and in electrophoretic mobility of the major bands (1).

Preliminary genetic studies showed that two of these patterns were con-

trolled by two alleles of one locus (2). The albumins corresponding to

the characteristic electrophoretic variants seemed to have a molecular

weight (MW) of approximately 40,000 and to consist of two subunits of MW

approximately 23,000 (3).

Recently, Murray reported that the subunits of MW 23,000 did not

disappear during germination of J?, sativum seeds and suggested that

these polypeptides could function as structural components (4).

The possible physiological role of the specific albumins was inves-

tigated by examining changes in electrophoretic albumin patterns during

seed germination of five Pisum lines, each with a distinct banding

pattern. Seeds of the following lines from the Weibullsholm collection

were investigated: WL 110 (P. sativum): WL 936 (P. humile): WL 1490

(P. cinereum) ; WL 808 (P. abyssinicum; and WL 1256 (P. fulvum). Seeds

were germinated in darkness on moist filter paper. Albumins were ex-

tracted from cotyledons at five-day intervals until the 20th day, with

0.15 M acetate buffer, pH 4.6 or with 5% K₂SO₄ in 0.1 M Na-phosphate,

pH 7.0 according to Murray (4). Native proteins were submitted to disc-

electrophoresis , dissociated proteins to SDS-electrophoresis, as

described elsewhere (3).

Extracts obtained both in pH 4.6 and in pH 7.0 gave generally

similar electrophoretic spectra. The electrophoretic patterns of the

albumins from germinating seeds of the five lines are shown in Fig. 1.

In general, the characteristic patterns persisted until the 20th day.

Some alterations were observed only in P. abyssinicum and P. cinereum.

In P. abyssinicum the characteristic band "f" split into two about the

10th day; in P. cinereum the bands "b" and "d" became faint ap-

proximately after the 15th day. The latter observation should be

interpreted with caution, because the relative intensities of the bands

"c" and "d" in P. cinereum were known to vary depending on uncontrolled

This work was performed under Government Project PR-4

PNL Volume 14

1982

RESEARCH REPORTS

experimental conditions (unpublished results). It could be assumed that

the albumins corresponding to these bands are labile and can be easily

transformed into one another.

SDS-electrophoresis of the albumins from germinating seeds of the

five pea lines gave similar results for each line studied. Polypeptide

of MW 23,000 did not disappear during three weeks of germination

(Fig. 2).

The results reported here indicate that the specific albumins of

the five lines have a similar physiological function. These data also

confirm the observation of Murray (4) for P. sativum: the polypeptides

of MW 23,000 seemed not to be utilized during seed germination. It is

possible that the albumins corresponding to these subunits could func-

tion as structural components, but further studies are required to prove

this hypothesis.

X . »

Fig. 2 . SDS-electrophoresis of the albumins extracted from cotyledons

after 20 days of germination. The Pisum forms are denoted as in

Fig. 1.

1. Przybylska, J., S. Blixt, J. Hurich, and Z. Zimniak-Przybylska.

1977. Genetica Polonica 18:27-38.

2. Blixt, S. , J. Przybylska, and Z. Zimniak-Przybylska. 1980.

Genetica Polonica 21:153-161.

3. Jakubek, M. and J. Przybylska. 1979. Genetica Polonica 20:369-380.

4. Murray, D. R. 1979. Plant, Cell and Environment 2:221-226.



	PNL Volume 14 1982	RESEARCH REPORTS 27



	Fig. 1. Gel electrophoresis of the albumins extracted from cotyledons of germinating seeds of five diverse Pisum lines. 0 — start- ing material (dormant seeds); 5, 10, 15, 20 days of germination, a-f characteristic bands. I W 110 (P. sativum ) ; II--W9 3 6 (P. humile ) : III - W 14 90 P. ci nereum: IV — W 808 (P. abyssinicum):V — W 1256 (P. fulvum).