Lettuce seed germination: modulation of pregermination protein synthesis by gibberellic Acid, abscisic Acid, and cytokinin.

نویسندگان

  • D W Fountain
  • J D Bewley
چکیده

Protein synthesis in gibberellin-treated lettuce (Lactuca sativa) seeds has been studied during the lag phase between the beginning of imbibition and the first signs of radicle protrusion. When compared to the water-imbibed controls, both polyribosome populations and radioactive leucine incorporation into protein increase in the embryos of GA(3)- induced seeds early in the imbibition period. Since these results are contradictory to previously published studies, the reasons for the differences are outlined and various alternative possibilities eliminated. The protocol for protein extraction, particularly the speed at which the supernatant from the seed homogenate is cleared, is important for demonstrating the GA(3)-mediated changes. Embryos maintained in the dormant state by abscisic acid still conduct considerable amounts of protein synthesis, and this is enhanced by concentrations of 6-benzylaminopurine which also promote germination. Therefore, the actions of GA(3), abscisic acid, and cytokinin on lettuce seed germination are mediated, directly or indirectly, via protein synthesis.

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

Inhibition of Gibberellic Acid-induced Germination by Abscisic Acid and Reversal by Cytokinins.

The germinatioil of seed can be controlled by ap)plication of exogenous hormones at physiological concenitrations. It is therefore possible that the n-atural control of germination involves an interplay of hormones, both promoters and inh,,ibitors. WXe have shown that cytokinins overcome the inhibitoryaction of several natural inhibitors in the germination of the photosensitive Grand Rapids let...

متن کامل

The gibberellic acid signaling repressor RGL2 inhibits Arabidopsis seed germination by stimulating abscisic acid synthesis and ABI5 activity.

Seed germination is antagonistically controlled by the phytohormones gibberellic acid (GA) and abscisic acid (ABA). GA promotes seed germination by enhancing the proteasome-mediated destruction of RGL2 (for RGA-LIKE2), a key DELLA factor repressing germination. By contrast, ABA blocks germination by inducing ABI5 (for ABA-INSENSITIVE5), a basic domain/leucine zipper transcription factor repress...

متن کامل

Expression of genes associated with the biosynthetic pathways of abscisic acid, gibberellin, and ethylene during the germination of lettuce seeds.

Seed germination and dormancy are complex phenomena that are controlled by many genes and environmental factors. Such genes are indicated by phytohormones that interact with each other, and may cause dormancy or promote seed germination. The objective of this study was to investigate gene expression associated with the biosynthetic pathways of abscisic acid (ABA), gibberellic acid (GA), and eth...

متن کامل

The NF-YC–RGL2 module integrates GA and ABA signalling to regulate seed germination in Arabidopsis

The antagonistic crosstalk between gibberellic acid (GA) and abscisic acid (ABA) plays a pivotal role in the modulation of seed germination. However, the molecular mechanism of such phytohormone interaction remains largely elusive. Here we show that three Arabidopsis NUCLEAR FACTOR-Y C (NF-YC) homologues NF-YC3, NF-YC4 and NF-YC9 redundantly modulate GA- and ABA-mediated seed germination. These...

متن کامل

Mode of action of gibberellic Acid and light on lettuce seed germination.

The seeds of lettuce (Lactuca sativa L. cv. Grand Rapids) germinate in darkness at 25 C when treated by gibberellic acid (GA(3)) for 1 hour following 2 hours of imbibition. The time of GA(3) application influences the rate and the final percentage of seeds that germinate. In contrast, red light illumination given at different times affects only the rate and not the final germination percentage....

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 4  شماره 

صفحات  -

تاریخ انتشار 1976