Starch degradation in the cotyledons of germinating lentils.

نویسندگان

  • J F Tárrago
  • G Nicolás
چکیده

Starch, total amylolytic and phosphorylase activities were determined in lentil cotyledons during the first days of germination. Several independent criteria show that the amylolytic activity is due mainly to an amylase of the alpha type. Starch is degraded slowly in the first days; during this time, alpha- and beta-amylase activity are very low, while phosphorylase increases and reach a peak on the 3rd day. On the 4th day, there is a more rapid depletion of starch which coincides with an increase in alpha-amylase activity. By polyacrylamide gel electrophoresis of the crude starch-degrading enzyme, five bands were obtained: one phosphorylase, three alpha-amylases, and one beta-amylase. Based on their heat lability or heat stability, two sets of alpha-amylase seem to exist in lentil cotyledons.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Fat Metabolism in Higher Plants XXXVI: Long Chain Fatty Acid Synthesis in Germinating Peas.

A low lipid, high starch containing tissue, namely cotyledons of germinating pea seedlings was examined for its capacity to synthesize fatty acid. Intact tissue slices readily incorporate acetate-(14)C into fatty acids from C(16) to C(24). Although crude homogenates synthesize primarily 16:0 and 18:0 from malonyl CoA, subsequent fractionation into a 10,000g pellet, a 10(5)g pellet and supernata...

متن کامل

Arginine catabolism in the cotyledons of developing and germinating pea seeds.

Arginine is the predominant free amino acid in the cotyledons of developing seeds of Pisum sativum L. cv Marzia. Breakdown of arginine was measured by injecting l-[guanido-(14)C]arginine into detached cotyledons. Cotyledons of developing seeds showed a low rate of (14)CO(2) evolution whereas a much higher rate of (14)CO(2) evolution was measured from cotyledons of seeds 4 days after the onset o...

متن کامل

Embryo is not required for initiation of alpha-amylase activity in germinating cowpea (Vigna unguiculata L.) seeds.

When embryonated and de-embryonated cotyledons of cowpea (Vigna unguiculata L.) were kept for germination, only embryonated cotyledons (EC) developed into seedlings. alpha-Amylase activity appeared late in de-embryonated cotyledons (DEC), but increased and matched with that of EC on 4th day, and thereafter started declining. A higher content of reducing sugars may be one of the factors in down ...

متن کامل

CysteineEndopeptidase from Vignamungo : Gene Structure and Expression

A cysteine endopeptidase (SH-EP) is involved in the degradation of storage globulin in cotyledons of germinating seeds of Vigna mungo. Using SH-EP cDNA as a probe, we isolated two oyerlapping genomic clones for SH-EP from a VL mungo genomic library, The results of Southern blot analysis of the nuclear DNA suggested that there is a single gene for SH-EP. The site of initiation f transcription wa...

متن کامل

Chemical genetics and cereal starch metabolism: structural basis of the non-covalent and covalent inhibition of barley β-amylase.

There are major issues regarding the proposed pathway for starch degradation in germinating cereal grain. Given the commercial importance but genetic intractability of the problem, we have embarked on a program of chemical genetics studies to identify and dissect the pathway and regulation of starch degradation in germinating barley grains. As a precursor to in vivo studies, here we report syst...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Plant physiology

دوره 58 5  شماره 

صفحات  -

تاریخ انتشار 1976