Species-specific reversal of stem xylem embolism after a prolonged drought correlates to endpoint concentration of soluble sugars

Accurate predictions of species distribution under current and future climate conditions require modeling efforts based on clear mechanistic relationships between climate variables and plant physiological functions. Vulnerability of leaves to xylem embolism is a key mechanistic trait that might be included in these modeling efforts. Here, we propose a simple set-up to measure leaf vulnerability to embolism on the basis of the optical method using a smartphone, a light source, and a notebook. Our data show that this proposed set-up can adequately quantify the vulnerability to xylem embolism of leaf major veins in Populus nigra and Ostrya carpinifolia, producing values consistent with those obtained in temperate tree species with other methods, allowing virtually any laboratory to quantify species-specific drought tolerance on the basis of a sound mechanistic trait.

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Xylem Embolism in the Palm Rhapis Excelsa

IAWA Journal ◽

10.1163/22941932-90000956 ◽

1985 ◽

Vol 6 (4) ◽

pp. 283-292 ◽

Cited By ~ 16

Author(s):

John S. Sperry

Keyword(s):

Flow Resistance ◽

Stomatal Closure ◽

Gas Embolism ◽

Hydraulic Architecture ◽

Pressure Potential ◽

Xylem Embolism ◽

Xylem Pressure ◽

Xylem Pressure Potential ◽

Prolonged Drought ◽

Xylem Flow

Xylem failure via gas embolism (cavitation) was investigated in Rhapis excelsa (Palmae). Embolism was detected using measurements of xylem flow resistance in excised stems and petioles: a decrease in resistance after the removal of flow-impeding embolisms by a pressure treatment indicated their previous presence in the axis. Results suggested that Rhapis avoids serious damage from embolism in at least four ways. 1) Xylem pressure potentials reached embolism-inducing levels (c. -2.90 MPa) only during prolonged drought. 2) When embolism did occur, it was confined to leaf xylem; stem xylem, most critical to shoot survival, remained fully functional. This is due in part to hydraulic architecture: 70 to 85% of shoot xylem resistance is in the leaf, and thus xylem pressures are much lower in leaves than stems. 3) Even during prolonged drought, the amount of embolism is probably limited by complete stomatal closure, which occurred at xylem pressure potentials of -3.20 ± 0.18 MPa. 4) Embolism is potentially reversible during prolonged rains, since embolism dissolved within 5 h at zero pressure (atmospheric), and xylem pressure potential can reach zero during extended rain.

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Turgor loss point and vulnerability to xylem embolism predict species‐specific risk of drought‐induced decline of urban trees

Plant Biology ◽

10.1111/plb.13355 ◽

2021 ◽

Author(s):

F. Petruzzellis ◽

E. Tordoni ◽

A. Di Bonaventura ◽

M. Tomasella ◽

S. Natale ◽

...

Keyword(s):

Urban Trees ◽

Xylem Embolism ◽

Turgor Loss Point ◽

Specific Risk ◽

Species Specific

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Comparison of pre-germination treatments in Lupinus spp. and their effects on germination and related solutes

Botanical Sciences ◽

10.17129/botsci.893 ◽

2017 ◽

Vol 95 (3) ◽

pp. 577

Author(s):

Edna Irene Bautista-Rodríguez ◽

Luz Del Carmen Lagunes-Espinoza ◽

Francisco Marcelo Lara-Viveros ◽

Mepivoseth Castelán-Estrada ◽

Víctor Conde-Martínez

Keyword(s):

Protein Concentration ◽

Reducing Sugars ◽

Soluble Sugars ◽

Amino Acid Content ◽

Physical Dormancy ◽

Agricultural Use ◽

Dry Sand ◽

Chemical Pretreatments ◽

Species Specific ◽

Physical And Chemical

Background. Physical dormancy in seeds of the genus Lupinus restricts their ecological or agricultural use.Hypothesis. This dormancy can be broken when seeds are subjected to physical and chemical pretreatments that increase germination, mobilize reserves and decrease ABA.Studied species. Seeds of Lupinus exaltatus (Le), L. campestris (Lc) and L. montanus (Lm) from Puebla, México.Methods. The following seven treatments, including a control, were applied: PG1 = 98 % H2SO4 for 15 min, PG2 = wet sand at 80 °C for 5 min, PG3 = wet sand at 35 °C for 8 h and 16 h at 25 °C, PG4 = dry sand at 80 °C for 7 min, PG5 = dry sand at 150 °C for 1 min, PG6 = H20 at 80 °C for 1 min, Control = untreated seeds. On days 0, 3, 5, 10 and 15 after seeding, we evaluated the percentage and rate of germination (GP and GR, respectively) and biochemical changes. Results. PG6 produced a higher GP in Le (41 %) and Lc (69 %), and PG1 produced a higher GP in Lm (37 %). In all three species, the highest GR was obtained with PG1 (1.95, 2.27 and 2.22 day-1 seeds, respectively). PG6 increased the protein concentration (53, 17, and 43 % for Le, Lc and Lm, respectively), amino acids (19, 44 and 31 %, respectively), reducing sugars (63, 18 and 96 %, respectively) and polyphenols (32, 55 and 75 %, respectively) but decreased soluble sugars (22, 29 and 23 %, respectively) and ABA relative to the control. Although only the correlation between the GP and amino acid content was significant and positive, and the correlation between GP, GR and soluble sugars was significant and negative.Conclusions. The effect of pre-germination treatments on germination was species-specific. The pretreatment with H20 at 80 °C for 1 min increased germination and mobilized the seed’s reserves in the process.

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Electron Microscopy in the Study of Natural Phytoplankton Assemblages

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119831 ◽

1985 ◽

Vol 43 ◽

pp. 620-623

Author(s):

Linda Sicko-Goad

Keyword(s):

Electron Microscopy ◽

Aquatic Environment ◽

Size Range ◽

Physical Parameters ◽

Specific Information ◽

Phytoplankton Assemblages ◽

Phytoplankton Productivity ◽

Ecosystem Effects ◽

Time Of Year ◽

Species Specific

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.

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