Embryo and endosperm development in wheat (Triticum aestivum L.) kernels subjected to drought stress.
The aim of the present work was to reveal the histological alterations triggered in developing wheat kernels by soil drought stress during early seed development resulting in yield losses at harvest. For this purpose, observations were made on the effect of drought stress, applied in a controlled environment from the 5th to the 9th day after pollination, on the kernel morphology, starch content and grain yield of the drought-sensitive Cappelle Desprez and drought-tolerant Plainsman V winter wheat (Triticum aestivum L.) varieties. As a consequence of water withdrawal, there was a decrease in the size of the embryos and the number of A-type starch granules deposited in the endosperm, while the development of aleurone cells and the degradation of the cell layers surrounding the ovule were significantly accelerated in both genotypes. In addition, the number of B-type starch granules per cell was significantly reduced. Drought stress affected the rate of grain filling shortened the grain-filling and ripening period and severely reduced the yield. With respect to the recovery of vegetative tissues, seed set and yield, the drought-tolerant Plainsman V responded significantly better to drought stress than Cappelle Desprez. The reduction in the size of the mature embryos was significantly greater in the sensitive genotype. Compared to Plainsman V, the endosperm cells of Cappelle Desprez accumulated significantly fewer B-type starch granules. In stressed kernels of the tolerant genotype, the accumulation of protein bodies occurred significantly earlier than in the sensitive variety.
Agricultural Research Institute of the Hungarian Academy of Sciences, Brunszvik 2, Martonvásár 2462, Hungary.
Attila
A
Fábián
Katalin
K
Jäger
Mariann
M
Rakszegi
Beáta
B
Barnabás
D055864:Droughts; D018506:Gene Expression Regulation, Plant; D008855:Microscopy, Electron, Scanning; D012639:Seeds / Q000196:embryology* / Q000378:metabolism / Q000648:ultrastructure; D014908:Triticum / Q000196:embryology* / Q000378:metabolism / Q000648:ultrastructure
Plant Cell Rep. 2010 Jan;29(1):37-50
19902215
Plant Mol Biol. 1999 Mar;39(5):915-26
10344197
Philos Trans R Soc Lond B Biol Sci. 2002 Feb 28;357(1418):133-42
11911770
Ann Bot. 2003 Jun;91(7):857-67
12730070
Plant Cell. 1994 Sep;6(9):1241-1252
12244271
Planta. 1978 Jan;140(1):19-30
24414356
J Ultrastruct Res. 1969 Jan;26(1):31-43
4887011
J Appl Physiol. 1962 Mar;17:343-8
14005589
Int J Biol Macromol. 1998 Aug;23(2):85-112
9730163
Plant Cell Environ. 2008 Jan;31(1):11-38
17971069
Planta. 1975 Jan;123(2):105-16
24435077