Leaf exogenous application of abscisic acid triggers tolerance mechanisms to water stress in rubber

Melo, Hyrandir Cabral de; Rodrigues, Fabrício Jesus; Queirós, Silas Ferreira; Portes, Tomás de Aquino

doi:10.5902/1980509825824

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Artigo • Ciênc. Florest. 29 (1) • Jan-Mar 2019 • https://doi.org/10.5902/1980509825824 copy

Leaf exogenous application of abscisic acid triggers tolerance mechanisms to water stress in rubber

Authorship SCIMAGO INSTITUTIONS RANKINGS

Abstract

The abscisic acid (ABA) is known as the most influential hormone in triggering mechanisms of stress tolerance in plants, including water deficit. However, the effect of ABA exogenous application as a pre-stress inducing tolerance is poorly studied in plants of agronomic interest. The purpose of this research was to evaluate the effect of ABA triggering mechanisms of stress tolerance in rubber tree seedlings, cultivar RRIM 600. The concentrations used were 0, 50, 100 or 200 µM applied weekly on leaves for 12 weeks, followed by the suspension of watering for 13 days. Leaves of the second node, from the basis to the apex, were analysed, using five plants per treatment (ABA concentration), which had more than six leaves completely expanded and cultivated in vases of 10 L with dark-red latosol. It was evaluated its influence on the potential quantum efficiency of photosystem II (Fv / Fm), measured daily during the suspension of irrigation, and on gas exchanges measured on days 0, 3, 7 and 10 after the suspension of irrigation. After 120 days of the end of the first period of watering suspension and after occurring natural abscission and leaf recovery, the plants were again submitted to a second period of 13 days of water suspension to check the residual effects of the prior application of ABA on untreated leaves. It was observed that the exogenous application of ABA induced drought tolerance, particularly in plants treated with 100 and 200 µM and caused residual effect of tolerance on untreated new leaves. It was observed that the first watering suspension itself triggered tolerance mechanisms observed during the second period of water suspension on ABA untreated plants. The foliar application of ABA triggers mechanisms that improve the tolerance of the plants to the water deficit to which the plants can be submitted.

Keywords:
ABA; Fluorescence; Photosynthesis; Hevea brasiliensis; Water deficit

Tabela 1 Eficiência fotoquímica potencial do fotossistema II (Fv/Fm) em mudas de seringueira (Hevea brasiliensis) tratadas durante 12 semanas com aplicação foliar de ácido abscísico (ABA), em diferentes concentrações, e submetidas a 13 dias de suspensão da rega (primeira suspensão da rega), e segunda suspensão da rega após 120 dias do final da primeira suspensão da rega (segunda suspensão da rega).

[ABA]	Dias após a primeira suspensão da rega (Days after the first water withholding)														CV
µM	0	1	2	3	4	5	6	7	8	9	10	11	12	13	(%)
0	0,82a^A	0,82a^A	0,79a^AB	0,78a^AB	0,63b^ABC	0,49b^BC	0,29b^CD	0,05b^D	0,02b^D	0,01c^D	0,01c^D	-	-	-	45,54
50	0,84a^A	0,83a^A	0,78a^A	0,78a^A	0,80ab^A	0,76a^AB	0,65a^AB	0,64a^AB	0,64a^AB	0,50b^BC	0,50b^BC	0,36b^C	-	-	20,26
100	0,82a^A	0,82a^A	0,78a^A	0,77a^A	0,80ab^A	0,81a^A	0,63a^A	0,68a^A	0,68a^A	0,70a^A	0,78a^A	0,80a^A	0,76a^A	0,64a^A	31,7
200	0,83a^A	0,83a^A	0,83a^A	0,83a^A	0,82a^A	0,82a^A	0,77a^AB	0,77a^AB	0,77a^AB	0,81a^AB	0,81a^AB	0,8a^AB	0,71a^AB	0,62a^B	12,44
%CV	2,99	2,97	3,86	3,9	13,79	17,71	18,12	16,07	25,22	24,47	25,1	24,47	16,64	35,83
[ABA]	Dias após a segunda suspensão da rega (Days after the first water withholding)														CV
µM	0	1	2	3	4	5	6	7	8	9	10	11	12	13	(%)
0	0,81ab^A	0,81ab^A	0,80a^A	0,80a^A	0,79a^A	0,79a^A	0,79a^A	0,78b^A	0,76a^A	0,70a^A	0,70a^A	0,48a^AB	0,47a^AB	0,31a^B	21,54
50	0,82a^A	0,82a^A	0,81a^A	0,81a^A	0,81a^A	0,80a^A	0,80a^A	0,80ab^A	0,78a^AB	0,70a^AB	0,71a^AB	0,49a^BC	0,48a^BC	0,35a^C	16,37
100	0,81a^A	0,81a^A	0,81a^A	0,81a^A	0,82a^A	0,81a^A	0,82a^A	0,81a^A	0,80a^A	0,81a^A	0,80a^A	0,64a^A	0,64a^A	0,52a^A	19,15
200	0,82ab^A	0,82ab^A	0,82a^A	0,82a^A	0,82a^A	0,82a^A	0,82a^A	0,81a^A	0,81a^A	0,82a^A	0,81a^A	0,80a^A	0,79a^A	0,47a ^B	9
%CV	1,45	1,47	1,34	1,3	1,79	1,82	1,9	1,58	3,98	24,2	25,1	42,45	43,1	66,31

Tabela 2 Trocas gasosas em mudas de seringueira (Hevea brasiliensis) tratadas durante 12 semanas com aplicação foliar de ácido abscísico (ABA), em diferentes concentrações, e submetidas à suspensão da rega (primeira suspensão da rega), e segunda suspensão da rega após 120 dias do final da primeira suspensão da rega (segunda suspensão da rega).

[ABA]	Dias após a primeira suspensão da rega (Days after the first water withholding)
µM	0	3	7	10
Fotossíntese líquida (Net photosynthesis) (µmol CO₂ m^-2 s^-1)
0	6,93 a^A ±0,34	4,82 a^A ±0,51	0,88 a^B ±2,32	-1,38 bc^B ±0,85
50	4,59 a^A ±0,77	3,21 a^AB±0,65	2,02 a^B±0,97	-1,43 c^C ±1,0
100	5,74 a^A ±0,87	3,21 a^AB ±0,92	1,30 a^B ±0,81	1,34 ab^B ±2,27
200	5,44 a^A ±0,89	4,81 a^A ±1,32	1,33 a^B ±0,64	1,38 a^B ±0,52
Condutância estomática (Stomatal conductance) (mol H₂O m^-2 s^-1)
0	0,232 a^A ±0,024	0,086 a^B ±0,020	0,034 a^C ±0,031	0,007 b^C ±0,007
50	0,154 b^A ±0,031	0,055 ab^A ±0,032	0,028 a^A ±0,007	0,014 b^A ±0,012
100	0,168 b^A ±0,031	0,038 b^B ±0,007	0,030 a^B ±0,008	0,047 a^B ±0,026
200	0,108 b^A ±0,036	0,060 ab^B ±0,024	0,034 a^B ±0,008	0,022 ab^B ±0,007
Transpiração (Transpiration) (mmol H₂O m^-2 s^-1)
0	4,132 a^A ±0,389	1,728 a^B ±0,318	1,192 a^AB ±0,961	0,260 b^B ±0,244
50	1,940 b^A ±0,081	1,180 ab^AB ±0,614	1,134 a^AB ±0,292	0,406 b^B ±0,327
100	1,912 b^A ±0,067	0,856 b^B ±0,167	1,322 a^AB ±0,429	1,280 a^AB ±0,638
200	2,084 b^A ±0,122	1,200 ab^B ±0,427	0,918 a^B ±0,368	0,770 ab^B ±0,210
Dias após a segunda suspensão da rega (Days after the second water withholding)
[ABA]	0	3	7	10
µM	Fotossíntese líquida (Net photosynthesis) (µmol CO₂ m^-2 s^-1)
0	4,09 a^A ±0,37	3,89 a^A ±0,69	1,88 a^A ±2,16	-0,99 a^B ±0,51
50	4,32 a^A ±0,78	4,06 a^A±1,25	3,94 a^A±1,04	-0,78 a^B ±0,27
100	4,40 a^AB ±0,61	5,05 a^A ±1,04	2,82 a^AB ±1,66	1,10 a^B ±1,94
200	3,87 a^AB ±0,21	5,64 a^A ±0,09	2,56 a^B ±1,21	-0,06 a^C ±0,28
Condutância estomática (Stomatal conductance) (mol H₂O m^-2 s^-1)
0	0,160 a^A ±0,037	0,147 a^AB ±0,033	0,055 a^BC ±0,058	0,006 a^C ±0,003
50	0,155 a^A ±0,035	0,140 a^A ±0,032	0,110 a^A ±0,050	0,008 a^B ±0,001
100	0,232 a^A ±0,034	0,157 a^A ±0,040	0,060 a^B ±0,039	0,029 a^B ±0,027
200	0,210 a^A ±0,012	0,132 a^AB ±0,083	0,060 a^BC ±0,057	0,008 a^C ±0,003
Transpiração (Transpiration) (mmol H₂O m^-2 s^-1)
0	2,410 b^AB ±0,362	3,225 a^A ±0,431	1,447 a^AB ±1,37	0,207 a^B ±0,059
50	2,640 b^AB ±0,400	3,275 a^A ±0,625	3,045 a^A ±1,175	0,260 a^B ±0,040
100	3,470 a^AB ±0,354	3,602 a^A ±0,673	1,840 a^AB ±1,038	0,927 a^B ±0,813
200	3,170 ab^A ±0,151	2,567 a^A ±1,242	1,492 a^A ±1,176	0,260 a^A ±0,107

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