scholarly journals Wood allocation trade‐offs between fiber wall, fiber lumen, and axial parenchyma drive drought resistance in neotropical trees

2020 ◽  
Vol 43 (4) ◽  
pp. 965-980 ◽  
Author(s):  
Thomas A. J. Janssen ◽  
Teemu Hölttä ◽  
Katrin Fleischer ◽  
Kim Naudts ◽  
Han Dolman
2020 ◽  
Vol 195 (4) ◽  
pp. 691-704 ◽  
Author(s):  
Ian S. Pearse ◽  
Jessica M. Aguilar ◽  
Sharon Y. Strauss

Oecologia ◽  
2020 ◽  
Vol 192 (4) ◽  
pp. 1023-1036 ◽  
Author(s):  
Eun-Young Jung ◽  
Julian Gaviria ◽  
Shanwen Sun ◽  
Bettina M. J. Engelbrecht

2020 ◽  
Vol 25 (4) ◽  
pp. 599-609
Author(s):  
Sarah Augustina ◽  
Imam Wahyudi ◽  
I Wayan Darmawan ◽  
Jamaludin Malik

The purpose of this study was to analyze anatomical characteristics, fiber morphology, and several important physical properties of nyatoh (Palaquium lanceolatum), pisang putih (Sindora walichii), and sepetir (Mezzettia leptopoda) wood from North Kalimantan in order to support the proper utilization of each wood species. All parameters were analyzed using their standard procedures. Results showed that anatomical characteristics of nyatoh wood are the vessels predominantly are in radial multiples and contained tyloses, ray parenchyma is mostly uniseriate and even, while axial parenchyma is in narrow tangential line with irregularly spaced. For pisang putih wood, the vessels are exclusively solitary, ray parenchyma of two distinct sizes, while axial parenchyma are in continuous tangential bands with irregularly spaced. In case of sepetir wood, the vessel is in radial and diagonal patterns, rays tend to have two different sizes, axial parenchyma is vasicentric to aliform, and has the axial resin canals in continuous tangential bands. Average values of fiber length and fiber wall thickness are 1904 and 3.61 µm (nyatoh), 1708 and 4.51 µm (pisang putih), and 1337 and 3.39 µm (sepetir), respectively; while the mean values of specific gravity and T/R-ratio are 0.42 and 1.41 (nyatoh), 0.37 and 2.34 (pisang putih), and 0.32 and 1.40 (sepetir), respectively. Nyatoh wood is categorized as the Strength Class of III, while pisang putih and sepetir woods are categorized as the Strength Class of IV. Compared to pisang putih and sepetir woods, nyatoh wood is more potential for pulp, paper, and furniture manufacturing. Keywords: anatomical characteristics, fiber morphology, lesser-used wood species, physical properties


2020 ◽  
Author(s):  
Dana M. Blumenthal ◽  
Daniel R. LeCain ◽  
Lauren M. Porensky ◽  
Elizabeth A. Leger ◽  
Rowan Gaffney ◽  
...  

2020 ◽  
Vol 40 (8) ◽  
pp. 1029-1042 ◽  
Author(s):  
Zhicheng Chen ◽  
Shidan Zhu ◽  
Yongtao Zhang ◽  
Junwei Luan ◽  
Shan Li ◽  
...  

Abstract Xylem traits are critical plant functional traits associated with water transport, mechanical support, and carbohydrate and water storage. Studies on the xylem hydraulic efficiency–safety tradeoff are numerous; however, the storage function of xylem parenchyma is rarely considered. The effects of a substantial number of xylem traits on water transport, embolism resistance, mechanical support, storage capacity and nonstructural carbohydrate (NSC) content were investigated in 19 temperate broadleaf species planted in an arid limestone habitat in northern China. There was no xylem hydraulic efficiency–safety tradeoff in the 19 broadleaf species. The total parenchyma fraction was negatively correlated with the fiber fraction. Embolism resistance was positively correlated with indicators of xylem mechanical strength such as vessel wall reinforcement, vessel wall thickness and fiber wall thickness, and was negatively related to the axial parenchyma fraction, especially the paratracheal parenchyma fraction. The paratracheal parenchyma fraction was positively correlated with the ratio of the paratracheal parenchyma fraction to the vessel fraction. In addition, the xylem NSC concentration was positively related to the total parenchyma fraction and axial parenchyma fraction. There was a storage capacity–embolism resistance tradeoff in the xylem of 19 broadleaf species in arid limestone habitats. We speculate that the temperate broadleaf species may show a spectrum of xylem hydraulic strategies, from the embolism resistance strategy related to a more negative P50 (the water potential corresponding to 50% loss of xylem conductivity) to the embolization repair strategy based on more paratracheal parenchyma.


Author(s):  
Mark E. De Guzman ◽  
Louis S. Santiago ◽  
Stefan A. Schnitzer ◽  
Leonor Álvarez-Cansino

Author(s):  
Mark E De Guzman ◽  
Aleyda Acosta-Rangel ◽  
Klaus Winter ◽  
Frederick C Meinzer ◽  
Damien Bonal ◽  
...  

Abstract Wood density (WD) is often used as a proxy for hydraulic traits such as vulnerability to drought-induced xylem cavitation and maximum water transport capacity, with dense-wooded species generally being more resistant to drought-induced xylem cavitation, having lower rates of maximum water transport and lower sapwood capacitance than light-wooded species. However, relationships between WD and the hydraulic traits that they aim to predict have not been well established in tropical forests, where modeling is necessary to predict drought responses for a high diversity of unmeasured species. We evaluated WD and relationships with stem xylem vulnerability by measuring cavitation curves, sapwood water release curves and minimum seasonal water potential (Ψmin) on upper canopy branches of six tree species and three liana species from a single wet tropical forest site in Panama. The objective was to better understand coordination and trade-offs among hydraulic traits and the potential utility of these relationships for modeling purposes. We found that parameters from sapwood water release curves such as capacitance, saturated water content and sapwood turgor loss point (Ψtlp,x) were related to WD, whereas stem vulnerability curve parameters were not. However, the water potential corresponding to 50% loss of hydraulic conductivity (P50) was related to Ψtlp,x and sapwood osmotic potential at full turgor (πo,x). Furthermore, species with lower Ψmin showed lower P50, Ψtlp,x and πo,x suggesting greater drought resistance. Our results indicate that WD is a good easy-to-measure proxy for some traits related to drought resistance, but not others. The ability of hydraulic traits such as P50 and Ψtlp,x to predict mortality must be carefully examined if WD values are to be used to predict drought responses in species without detailed physiological measurements.


2015 ◽  
Vol 58 ◽  
pp. 83-100 ◽  
Author(s):  
Selena Gimenez-Ibanez ◽  
Marta Boter ◽  
Roberto Solano

Jasmonates (JAs) are essential signalling molecules that co-ordinate the plant response to biotic and abiotic challenges, as well as co-ordinating several developmental processes. Huge progress has been made over the last decade in understanding the components and mechanisms that govern JA perception and signalling. The bioactive form of the hormone, (+)-7-iso-jasmonyl-l-isoleucine (JA-Ile), is perceived by the COI1–JAZ co-receptor complex. JASMONATE ZIM DOMAIN (JAZ) proteins also act as direct repressors of transcriptional activators such as MYC2. In the emerging picture of JA-Ile perception and signalling, COI1 operates as an E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S proteasome, thereby derepressing transcription factors such as MYC2, which in turn activate JA-Ile-dependent transcriptional reprogramming. It is noteworthy that MYCs and different spliced variants of the JAZ proteins are involved in a negative regulatory feedback loop, which suggests a model that rapidly turns the transcriptional JA-Ile responses on and off and thereby avoids a detrimental overactivation of the pathway. This chapter highlights the most recent advances in our understanding of JA-Ile signalling, focusing on the latest repertoire of new targets of JAZ proteins to control different sets of JA-Ile-mediated responses, novel mechanisms of negative regulation of JA-Ile signalling, and hormonal cross-talk at the molecular level that ultimately determines plant adaptability and survival.


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