Photosynthesis and assimilate partitioning between carbohydrates and isoprenoid products in vegetatively active and dormant guayule: physiological and environmental constraints on rubber accumulation in a semiarid shrub.
نویسندگان
چکیده
The stems and roots of the semiarid shrub guayule, Parthenium argentatum, contain a significant amount of natural rubber. Rubber accumulates in guayule when plants are vegetatively and reproductively dormant, complicating the relationship between growth/reproduction and product synthesis. To evaluate the factors regulating the partitioning of carbon to rubber, carbon assimilation and partitioning were measured in guayule plants that were grown under simulated summer- and winter-like conditions and under winter-like conditions with CO(2) enrichment. These conditions were used to induce vegetatively active and dormant states and to increase the source strength of vegetatively dormant plants, respectively. Rates of CO(2) assimilation, measured under growth temperatures and CO(2) , were similar for plants grown under summer- and winter-like conditions, but were higher with elevated CO(2) . After 5 months, plants grown under summer-like conditions had the greatest aboveground biomass, but the lowest levels of non-structural carbohydrates and rubber. In contrast, the amount of resin in the stems was similar under all growth conditions. Emission of biogenic volatile compounds was more than three-fold higher in plants grown under summer- compared with winter-like conditions. Taken together, the results show that guayule plants maintain a high rate of photosynthesis and accumulate non-structural carbohydrates and rubber in the vegetatively dormant state, but emit volatile compounds at a lower rate when compared with more vegetatively active plants. Enrichment with CO(2) in the vegetatively dormant state increased carbohydrate content but not the amount of rubber, suggesting that partitioning of assimilate to rubber is limited by sink strength in guayule.
منابع مشابه
Activities of fructan- metabolizing enzymes in barley stems subjected to terminal drought stress
Barley crop grown in semiarid areas may experience water deficit especially during grain filling that makes them more dependent on stem water-soluble carbohydrates (WSC). Fructans are the most important reserved carbohydrates. A pot experiment was undertaken at Shahid Chamran university in the duration of 2010-2011 growing seasons to investigate the accumulation and loss of WSC and the activity...
متن کاملInteraction of nitrogen stress and salicylic acid on the physiological characteristics of borage
Deficiency of nitrogen may lead to decrease in yield and yield potential of crop plants. An experiment was done under glasshouse conditions in order to investigate nitrogen levels and salicylic acid interaction on some physiologic traits of borage (Borago officinials L.). In this experiment various levels of nitrogen (including; 27.5, 55, 110, 220 and 330 mg/L from ammonium nitrate) and salicyl...
متن کاملActivities of fructan- metabolizing enzymes in barley stems subjected to terminal drought stress
Barley crop grown in semiarid areas may experience water deficit especially during grain filling that makes them more dependent on stem water-soluble carbohydrates (WSC). Fructans are the most important reserved carbohydrates. A pot experiment was undertaken at Shahid Chamran university in the duration of 2010-2011 growing seasons to investigate the accumulation and loss of WSC and the activity...
متن کاملAssimilate partitioning in leaves of the raffinose-storing herb Lamium album L.: photosynthesis and carbon partitioning throughout the photoperiod
(Assimilate partitioning in leaves of the raffinose-storing herb Lamium album L.: photosynthesis and carbon partitioning throughout the photoperiod). Lamium album accumulates starch, sucrose and raffinose-family oligosaccharides (RFO) as the major products of photosynthesis. These products were measured in leaves throughout a sixteen-hour photoperiod and under various irradiance conditions. The...
متن کاملIon content and its correlation with some physiological parameters in olive cultivars in response to salinity
ABSTRACT- Olive (Olea europaea L.) is one of the most valuable and widespread fruit trees in Iran. Salt stress-induced changes in membrane stability, photosynthesis and antioxidant enzyme activity were examined on four olive cultivars (Dakal, Shiraz, Zard and Amigdalifolia) by emphasizing the correlation between measured parameters and ion (K+, Na+) accumulation. Plants were subjected to four s...
متن کاملذخیره 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 ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physiologia plantarum
دوره 140 4 شماره
صفحات -
تاریخ انتشار 2010