Separating active and passive influences on stomatal control of transpiration.
نویسندگان
چکیده
Motivated by studies suggesting that the stomata of ferns and lycophytes do not conform to the standard active abscisic acid (ABA) -mediated stomatal control model, we examined stomatal behavior in a conifer species (Metasequoia glyptostroboides) that is phylogenetically midway between the fern and angiosperm clades. Similar to ferns, daytime stomatal closure in response to moderate water stress seemed to be a passive hydraulic process in M. glyptostroboides immediately alleviated by rehydrating excised shoots. Only after prolonged exposure to more extreme water stress did active ABA-mediated stomatal closure become important, because foliar ABA production was triggered after leaf turgor loss. The influence of foliar ABA on stomatal conductance and stomatal aperture was highly predictable and additive with the passive hydraulic influence. M. glyptostroboides thus occupies a stomatal behavior type intermediate between the passively controlled ferns and the characteristic ABA-dependent stomatal closure described in angiosperm herbs. These results highlight the importance of considering phylogeny as a major determinant of stomatal behavior.
منابع مشابه
Evidence for Active Uptake and Deposition of Si-based Defenses in Tall Fescue
Silicon (Si) is taken up from the soil as monosilicic acid by plant roots, transported to leaves and deposited as phytoliths, amorphous silica (SiO2) bodies, which are a key component of anti-herbivore defense in grasses. Silicon transporters have been identified in many plant species, but the mechanisms underpinning Si transport remain poorly understood. Specifically, the extent to which Si up...
متن کاملStomatal closure is induced by hydraulic signals and maintained by ABA in drought-stressed grapevine
Water saving under drought stress is assured by stomatal closure driven by active (ABA-mediated) and/or passive (hydraulic-mediated) mechanisms. There is currently no comprehensive model nor any general consensus about the actual contribution and relative importance of each of the above factors in modulating stomatal closure in planta. In the present study, we assessed the contribution of passi...
متن کاملControl of transpiration by radiation.
The terrestrial hydrological cycle is strongly influenced by transpiration--water loss through the stomatal pores of leaves. In this report we present studies showing that the energy content of radiation absorbed by the leaf influences stomatal control of transpiration. This observation is at odds with current concepts of how stomata sense and control transpiration, and we suggest an alternativ...
متن کاملExpression of Arabidopsis Hexokinase in Citrus Guard Cells Controls Stomatal Aperture and Reduces Transpiration
Hexokinase (HXK) is a sugar-phosphorylating enzyme involved in sugar-sensing. It has recently been shown that HXK in guard cells mediates stomatal closure and coordinates photosynthesis with transpiration in the annual species tomato and Arabidopsis. To examine the role of HXK in the control of the stomatal movement of perennial plants, we generated citrus plants that express Arabidopsis HXK1 (...
متن کاملEnvironmental controls on sap flow in a northern hardwood forest.
Our objective was to gain a detailed understanding of how photosynthetically active radiation (PAR), vapor pressure deficit (D) and soil water interact to control transpiration in the dominant canopy species of a mixed hardwood forest in northern Lower Michigan. An improved understanding of how these environmental factors affect whole-tree water use in unmanaged ecosystems is necessary in asses...
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:
- Plant physiology
دوره 164 4 شماره
صفحات -
تاریخ انتشار 2014