TY - JOUR
T1 - Leaf structure affects a plant’s appearance
T2 - combined multiple-mechanisms intensify remarkable foliar variegation
AU - Chen, Yun Shiuan
AU - Chesson, Peter
AU - Wu, Ho Wei
AU - Pao, Shang Hung
AU - Liu, Jian Wei
AU - Chien, Lee Feng
AU - Yong, Jean W.H.
AU - Sheue, Chiou Rong
N1 - Funding Information:
The authors thank the editor and two anonymous reviewers for valuable comments and suggestions, Dr. Cecilia Koo of the Botanic Conservation Center (KBCC) in Pingtung, Taiwan for providing Kamepferia (K040469) for this study, Huisun Experimental Forest of National Chung Hsing University for providing a permit to collect the plant materials of Blastus; nurseries in Singapore for providing materials of Sonerila, Dr. W. M. Chou (National Chiayi University) for providing a microslicer, and Dr. W. T. Chao (Tunghai University) and Miss P. C. Chaw (National Chung Hsing University) for help with TEM. This study was partially supported by the Ministry of Science and Technology [MOST-97-2126-B-005-002-MY3; MOST 104-2621-B-005-002-MY3], Taiwan.
Publisher Copyright:
© 2016, The Botanical Society of Japan and Springer Japan.
PY - 2017/3/1
Y1 - 2017/3/1
N2 - The presence of foliar variegation challenges perceptions of leaf form and functioning. But variegation is often incorrectly identified and misinterpreted. The striking variegation found in juvenile Blastus cochinchinensis (Melastomataceae) provides an instructive case study of mechanisms and their ecophysiological implications. Variegated (white and green areas, vw and vg) and non-variegated leaves (normal green leaves, ng) of seedlings of Blastus were compared structurally with microtechniques, and characterized for chlorophyll content and fluorescence. More limited study of Sonerila heterostemon (Melastomataceae) and Kaempferia pulchra (Zingiberaceae) tested the generality of the findings. Variegation in Blastus combines five mechanisms: epidermal, air space, upper mesophyll, chloroplast and crystal, the latter two being new mechanisms. All mesophyll cells (vw, vg, ng) have functional chloroplasts with dense thylakoids. The vw areas are distinguished by flatter adaxial epidermal cells and central trichomes containing crystals, the presence of air spaces between the adaxial epidermis and a colorless spongy-like upper mesophyll containing smaller and fewer chloroplasts. The vw area is further distinguished by having the largest spongy-tissue chloroplasts and fewer stomata. Both leaf types have similar total chlorophyll content and similar Fv/Fm (maximum quantum yield of PSII), but vg has significantly higher Fv/Fm than ng. Variegation in Sonerila and Kaempferia is also caused by combined mechanisms, including the crystal type in Kaempferia. This finding of combined mechanisms in three different species suggests that combined mechanisms may occur more commonly in nature than current understanding. The combined mechanisms in Blastus variegated leaves represent intricate structural modifications that may compensate for and minimize photosynthetic loss, and reflect changing plant needs.
AB - The presence of foliar variegation challenges perceptions of leaf form and functioning. But variegation is often incorrectly identified and misinterpreted. The striking variegation found in juvenile Blastus cochinchinensis (Melastomataceae) provides an instructive case study of mechanisms and their ecophysiological implications. Variegated (white and green areas, vw and vg) and non-variegated leaves (normal green leaves, ng) of seedlings of Blastus were compared structurally with microtechniques, and characterized for chlorophyll content and fluorescence. More limited study of Sonerila heterostemon (Melastomataceae) and Kaempferia pulchra (Zingiberaceae) tested the generality of the findings. Variegation in Blastus combines five mechanisms: epidermal, air space, upper mesophyll, chloroplast and crystal, the latter two being new mechanisms. All mesophyll cells (vw, vg, ng) have functional chloroplasts with dense thylakoids. The vw areas are distinguished by flatter adaxial epidermal cells and central trichomes containing crystals, the presence of air spaces between the adaxial epidermis and a colorless spongy-like upper mesophyll containing smaller and fewer chloroplasts. The vw area is further distinguished by having the largest spongy-tissue chloroplasts and fewer stomata. Both leaf types have similar total chlorophyll content and similar Fv/Fm (maximum quantum yield of PSII), but vg has significantly higher Fv/Fm than ng. Variegation in Sonerila and Kaempferia is also caused by combined mechanisms, including the crystal type in Kaempferia. This finding of combined mechanisms in three different species suggests that combined mechanisms may occur more commonly in nature than current understanding. The combined mechanisms in Blastus variegated leaves represent intricate structural modifications that may compensate for and minimize photosynthetic loss, and reflect changing plant needs.
KW - Blastus cochinchinensis
KW - Chloroplast
KW - Crystal
KW - Kaempferia pulchra
KW - Physical color
KW - Sonerila heterostemon
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U2 - 10.1007/s10265-016-0890-4
DO - 10.1007/s10265-016-0890-4
M3 - Article
C2 - 27995375
AN - SCOPUS:85006445910
SN - 0918-9440
VL - 130
SP - 311
EP - 325
JO - Journal of Plant Research
JF - Journal of Plant Research
IS - 2
ER -