Turnover of fatty acids during natural senescence of Arabidopsis, Brachypodium, and switchgrass and in Arabidopsis beta-oxidation mutants.

نویسندگان

  • Zhenle Yang
  • John B Ohlrogge
چکیده

During leaf senescence, macromolecule breakdown occurs and nutrients are translocated to support growth of new vegetative tissues, seeds, or other storage organs. In this study, we determined the fatty acid levels and profiles in Arabidopsis (Arabidopsis thaliana), Brachypodium distachyon, and switchgrass (Panicum virgatum) leaves during natural senescence. In young leaves, fatty acids represent 4% to 5% of dry weight and approximately 10% of the chemical energy content of the leaf tissues. In all three species, fatty acid levels in leaves began to decline at the onset of leaf senescence and progressively decreased as senescence advanced, resulting in a greater than 80% decline in fatty acids on a dry weight basis. During senescence, Arabidopsis leaves lost 1.6% of fatty acids per day at a rate of 2.1 mug per leaf (0.6 mug mg(-1) dry weight). Triacylglycerol levels remained less than 1% of total lipids at all stages. In contrast to glycerolipids, aliphatic surface waxes of Arabidopsis leaves were much more stable, showing only minor reduction during senescence. We also examined three Arabidopsis mutants, acx1acx2, lacs6lacs7, and kat2, which are blocked in enzyme activities of beta-oxidation and are defective in lipid mobilization during seed germination. In each case, no major differences in the fatty acid contents of leaves were observed between these mutants and the wild type, indicating that several mutations in beta-oxidation that cause reduced breakdown of reserve oil in seeds do not substantially reduce the degradation of fatty acids during leaf senescence.

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

Molecular genetic control of leaf lifespan in plants - A review

Leaf senescence constitutes the last stage of leaf development in plants and proceeds through a highly regulated program in order to redistribution of micro- and macro-nutrients from the senescing leaves to the developing/growing plant organs. Initiation and progression of leaf senescence is accompanied by massive sequential alterations at various levels of leaf biology including leaf morpholog...

متن کامل

Isolation and molecular characterization of the RecQsim gene in Arabidopsis, rice (Oryza sativa) and rape (Brassica napus)

In any organism that reproduces sexually, DNA Recombination plays vital roles in the generation of allelic diversity as well as in preservation of genome fidelity. Genome fidelity is particularly important in plants because mutations occurring during the development of flowering plants are heritable and can be passed onto the next generation. One of the gene families that play crucial roles in ...

متن کامل

2,4-Dichlorophenoxybutyric acid-resistant mutants of Arabidopsis have defects in glyoxysomal fatty acid beta-oxidation.

It has been demonstrated previously that 2,4-dichlorophenoxybutyric acid (2,4-DB) is metabolized to produce a herbicide, 2,4-D, by the action of peroxisomal fatty acid beta-oxidation in higher plants. To isolate mutants that have defects in peroxisomal fatty acid beta-oxidation, we screened mutant lines of Arabidopsis seedlings for growth in the presence of toxic levels of 2,4-DB. Twelve of the...

متن کامل

The critical role of Arabidopsis electron-transfer flavoprotein:ubiquinone oxidoreductase during dark-induced starvation.

In mammals, electron-transfer flavoprotein:ubiquinone oxidoreductase (ETFQO) and electron-transfer flavoprotein (ETF) are functionally associated, and ETF accepts electrons from at least nine mitochondrial matrix flavoprotein dehydrogenases and transfers them to ubiquinone in the inner mitochondrial membrane. In addition, the mammalian ETF/ETFQO system plays a key role in beta-oxidation of fatt...

متن کامل

ویژگی‌های بیوشیمیایی گیاهان آرابیدوپسیس جهش‌یافته ntrc طی پیری القاء ‌شده توسط تاریکی

Abstract Thioredoxins are invoved in redox regulation of many cellular processes. In this study the role of NADP+-Thioredoxin reductase C (NTRC) in the control of leaf senescence was investigated by biochemical characterization of Arabidopsis ntrc mutants. Forty days old wild type and two ntrc mutant lines were incubated either under normal dark-light or continous darkness regimes for 6 days as...

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 150 4  شماره 

صفحات  -

تاریخ انتشار 2009